diff options
70 files changed, 729 insertions, 731 deletions
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index f5929e4f79..94a3deed6f 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/advanced.sgml,v 1.52 2006/10/21 23:12:57 tgl Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/advanced.sgml,v 1.53 2007/01/31 20:56:16 momjian Exp $ --> <chapter id="tutorial-advanced"> <title>Advanced Features</title> @@ -57,7 +57,7 @@ SELECT * FROM myview; <para> Making liberal use of views is a key aspect of good SQL database design. Views allow you to encapsulate the details of the - structure of your tables, which may change as your application + structure of your tables, which might change as your application evolves, behind consistent interfaces. </para> @@ -250,7 +250,7 @@ COMMIT; <note> <para> Some client libraries issue <command>BEGIN</> and <command>COMMIT</> - commands automatically, so that you may get the effect of transaction + commands automatically, so that you might get the effect of transaction blocks without asking. Check the documentation for the interface you are using. </para> diff --git a/doc/src/sgml/arch-dev.sgml b/doc/src/sgml/arch-dev.sgml index 16d83bb1e6..c861a656e9 100644 --- a/doc/src/sgml/arch-dev.sgml +++ b/doc/src/sgml/arch-dev.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/arch-dev.sgml,v 2.28 2006/09/16 00:30:11 momjian Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/arch-dev.sgml,v 2.29 2007/01/31 20:56:16 momjian Exp $ --> <chapter id="overview"> <title>Overview of PostgreSQL Internals</title> @@ -272,7 +272,7 @@ similar to the raw parse tree in most places, but it has many differences in detail. For example, a <structname>FuncCall</> node in the parse tree represents something that looks syntactically like a function - call. This may be transformed to either a <structname>FuncExpr</> + call. This might be transformed to either a <structname>FuncExpr</> or <structname>Aggref</> node depending on whether the referenced name turns out to be an ordinary function or an aggregate function. Also, information about the actual data types of columns and expression @@ -342,7 +342,7 @@ <note> <para> In some situations, examining each possible way in which a query - may be executed would take an excessive amount of time and memory + can be executed would take an excessive amount of time and memory space. In particular, this occurs when executing queries involving large numbers of join operations. In order to determine a reasonable (not optimal) query plan in a reasonable amount of @@ -414,7 +414,7 @@ scanned in parallel, and matching rows are combined to form join rows. This kind of join is more attractive because each relation has to be scanned only once. - The required sorting may be achieved either by an explicit sort + The required sorting might be achieved either by an explicit sort step, or by scanning the relation in the proper order using an index on the join key. </para> @@ -502,7 +502,7 @@ </para> <para> - Complex queries may involve many levels of plan nodes, but the general + Complex queries can involve many levels of plan nodes, but the general approach is the same: each node computes and returns its next output row each time it is called. Each node is also responsible for applying any selection or projection expressions that were assigned to it by @@ -518,7 +518,7 @@ into the target table specified for the <command>INSERT</>. (A simple <command>INSERT ... VALUES</> command creates a trivial plan tree consisting of a single <literal>Result</> node, which computes just one - result row. But <command>INSERT ... SELECT</> may demand the full power + result row. But <command>INSERT ... SELECT</> can demand the full power of the executor mechanism.) For <command>UPDATE</>, the planner arranges that each computed row includes all the updated column values, plus the <firstterm>TID</> (tuple ID, or row ID) of the original target row; diff --git a/doc/src/sgml/array.sgml b/doc/src/sgml/array.sgml index db3fb7a423..4bfbfc0c54 100644 --- a/doc/src/sgml/array.sgml +++ b/doc/src/sgml/array.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/array.sgml,v 1.54 2007/01/31 04:12:01 momjian Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/array.sgml,v 1.55 2007/01/31 20:56:16 momjian Exp $ --> <sect1 id="arrays"> <title>Arrays</title> @@ -63,7 +63,7 @@ CREATE TABLE tictactoe ( </para> <para> - An alternative syntax, which conforms to the SQL standard, may + An alternative syntax, which conforms to the SQL standard, can be used for one-dimensional arrays. <structfield>pay_by_quarter</structfield> could have been defined as: @@ -88,7 +88,7 @@ CREATE TABLE tictactoe ( To write an array value as a literal constant, enclose the element values within curly braces and separate them by commas. (If you know C, this is not unlike the C syntax for initializing - structures.) You may put double quotes around any element value, + structures.) You can put double quotes around any element value, and must do so if it contains commas or curly braces. (More details appear below.) Thus, the general format of an array constant is the following: @@ -155,7 +155,7 @@ SELECT * FROM sal_emp; </para> <para> - The <literal>ARRAY</> constructor syntax may also be used: + The <literal>ARRAY</> constructor syntax can also be used: <programlisting> INSERT INTO sal_emp VALUES ('Bill', @@ -333,7 +333,7 @@ UPDATE sal_emp SET pay_by_quarter = ARRAY[25000,25000,27000,27000] WHERE name = 'Carol'; </programlisting> - An array may also be updated at a single element: + An array can also be updated at a single element: <programlisting> UPDATE sal_emp SET pay_by_quarter[4] = 15000 @@ -453,7 +453,7 @@ SELECT array_dims(ARRAY[1,2] || ARRAY[[3,4],[5,6]]); Note that the concatenation operator discussed above is preferred over direct use of these functions. In fact, the functions exist primarily for use - in implementing the concatenation operator. However, they may be directly + in implementing the concatenation operator. However, they might be directly useful in the creation of user-defined aggregates. Some examples: <programlisting> @@ -525,7 +525,7 @@ SELECT * FROM sal_emp WHERE 10000 = ALL (pay_by_quarter); <tip> <para> Arrays are not sets; searching for specific array elements - may be a sign of database misdesign. Consider + can be a sign of database misdesign. Consider using a separate table with a row for each item that would be an array element. This will be easier to search, and is likely to scale up better to large numbers of elements. @@ -592,7 +592,7 @@ SELECT f1[1][-2][3] AS e1, f1[1][-1][5] AS e2 or backslashes disables this and allows the literal string value <quote>NULL</> to be entered. Also, for backwards compatibility with pre-8.2 versions of <productname>PostgreSQL</>, the <xref - linkend="guc-array-nulls"> configuration parameter may be turned + linkend="guc-array-nulls"> configuration parameter might be turned <literal>off</> to suppress recognition of <literal>NULL</> as a NULL. </para> @@ -611,8 +611,8 @@ SELECT f1[1][-2][3] AS e1, f1[1][-1][5] AS e2 </para> <para> - You may write whitespace before a left brace or after a right - brace. You may also write whitespace before or after any individual item + You can write whitespace before a left brace or after a right + brace. You can also write whitespace before or after any individual item string. In all of these cases the whitespace will be ignored. However, whitespace within double-quoted elements, or surrounded on both sides by non-whitespace characters of an element, is not ignored. diff --git a/doc/src/sgml/backup.sgml b/doc/src/sgml/backup.sgml index 858e0564dc..9fc4445bbe 100644 --- a/doc/src/sgml/backup.sgml +++ b/doc/src/sgml/backup.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/backup.sgml,v 2.95 2006/12/01 03:29:15 tgl Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/backup.sgml,v 2.96 2007/01/31 20:56:16 momjian Exp $ --> <chapter id="backup"> <title>Backup and Restore</title> @@ -124,7 +124,7 @@ psql <replaceable class="parameter">dbname</replaceable> < <replaceable class <para> By default, the <application>psql</> script will continue to - execute after an SQL error is encountered. You may wish to use the + execute after an SQL error is encountered. You might wish to use the following command at the top of the script to alter that behaviour and have <application>psql</application> exit with an exit status of 3 if an SQL error occurs: @@ -138,7 +138,7 @@ psql <replaceable class="parameter">dbname</replaceable> < <replaceable class passing the <option>-1</> or <option>--single-transaction</> command-line options to <application>psql</>. When using this mode, be aware that even the smallest of errors can rollback a - restore that has already run for many hours. However, that may + restore that has already run for many hours. However, that might still be preferable to manually cleaning up a complex database after a partially restored dump. </para> @@ -325,7 +325,7 @@ tar -cf backup.tar /usr/local/pgsql/data <listitem> <para> If you have dug into the details of the file system layout of the - database, you may be tempted to try to back up or restore only certain + database, you might be tempted to try to back up or restore only certain individual tables or databases from their respective files or directories. This will <emphasis>not</> work because the information contained in these files contains only half the @@ -360,7 +360,7 @@ tar -cf backup.tar /usr/local/pgsql/data </para> <para> - If your database is spread across multiple file systems, there may not + If your database is spread across multiple file systems, there might not be any way to obtain exactly-simultaneous frozen snapshots of all the volumes. For example, if your data files and WAL log are on different disks, or if tablespaces are on different file systems, it might @@ -437,7 +437,7 @@ tar -cf backup.tar /usr/local/pgsql/data Since we can string together an indefinitely long sequence of WAL files for replay, continuous backup can be achieved simply by continuing to archive the WAL files. This is particularly valuable for large databases, where - it may not be convenient to take a full backup frequently. + it might not be convenient to take a full backup frequently. </para> </listitem> <listitem> @@ -465,7 +465,7 @@ tar -cf backup.tar /usr/local/pgsql/data <para> As with the plain file-system-backup technique, this method can only support restoration of an entire database cluster, not a subset. - Also, it requires a lot of archival storage: the base backup may be bulky, + Also, it requires a lot of archival storage: the base backup might be bulky, and a busy system will generate many megabytes of WAL traffic that have to be archived. Still, it is the preferred backup technique in many situations where high reliability is needed. @@ -534,7 +534,7 @@ archive_command = 'cp -i %p /mnt/server/archivedir/%f </dev/null' </programlisting> which will copy archivable WAL segments to the directory <filename>/mnt/server/archivedir</>. (This is an example, not a - recommendation, and may not work on all platforms.) + recommendation, and might not work on all platforms.) </para> <para> @@ -601,7 +601,7 @@ archive_command = 'test ! -f .../%f && cp %p .../%f' <para> In writing your archive command, you should assume that the file names to - be archived may be up to 64 characters long and may contain any + be archived can be up to 64 characters long and can contain any combination of ASCII letters, digits, and dots. It is not necessary to remember the original relative path (<literal>%p</>) but it is necessary to remember the file name (<literal>%f</>). @@ -614,7 +614,7 @@ archive_command = 'test ! -f .../%f && cp %p .../%f' <filename>postgresql.conf</>, <filename>pg_hba.conf</> and <filename>pg_ident.conf</>), since those are edited manually rather than through SQL operations. - You may wish to keep the configuration files in a location that will + You might wish to keep the configuration files in a location that will be backed up by your regular file system backup procedures. See <xref linkend="runtime-config-file-locations"> for how to relocate the configuration files. @@ -732,7 +732,7 @@ SELECT pg_stop_backup(); between <function>pg_start_backup</> and the start of the actual backup, nor between the end of the backup and <function>pg_stop_backup</>; a few minutes' delay won't hurt anything. (However, if you normally run the - server with <varname>full_page_writes</> disabled, you may notice a drop + server with <varname>full_page_writes</> disabled, you might notice a drop in performance between <function>pg_start_backup</> and <function>pg_stop_backup</>, since <varname>full_page_writes</> is effectively forced on during backup mode.) You must ensure that these @@ -750,7 +750,7 @@ SELECT pg_stop_backup(); </para> <para> - You may, however, omit from the backup dump the files within the + You can, however, omit from the backup dump the files within the <filename>pg_xlog/</> subdirectory of the cluster directory. This slight complication is worthwhile because it reduces the risk of mistakes when restoring. This is easy to arrange if @@ -775,7 +775,7 @@ SELECT pg_stop_backup(); the file system backup and the WAL segment files used during the backup (as specified in the backup history file), all archived WAL segments with names numerically less are no longer needed to recover - the file system backup and may be deleted. However, you should + the file system backup and can be deleted. However, you should consider keeping several backup sets to be absolutely certain that you can recover your data. </para> @@ -842,7 +842,7 @@ SELECT pg_stop_backup(); require that you have enough free space on your system to hold two copies of your existing database. If you do not have enough space, you need at the least to copy the contents of the <filename>pg_xlog</> - subdirectory of the cluster data directory, as it may contain logs which + subdirectory of the cluster data directory, as it might contain logs which were not archived before the system went down. </para> </listitem> @@ -881,7 +881,7 @@ SELECT pg_stop_backup(); <listitem> <para> Create a recovery command file <filename>recovery.conf</> in the cluster - data directory (see <xref linkend="recovery-config-settings">). You may + data directory (see <xref linkend="recovery-config-settings">). You might also want to temporarily modify <filename>pg_hba.conf</> to prevent ordinary users from connecting until you are sure the recovery has worked. </para> @@ -917,7 +917,7 @@ SELECT pg_stop_backup(); <filename>recovery.conf</> is the <varname>restore_command</>, which tells <productname>PostgreSQL</> how to get back archived WAL file segments. Like the <varname>archive_command</>, this is - a shell command string. It may contain <literal>%f</>, which is + a shell command string. It can contain <literal>%f</>, which is replaced by the name of the desired log file, and <literal>%p</>, which is replaced by the path name to copy the log file to. (The path name is relative to the working directory of the server, @@ -1228,8 +1228,8 @@ restore_command = 'copy /mnt/server/archivedir/%f "%p"' # Windows It should also be noted that the default <acronym>WAL</acronym> format is fairly bulky since it includes many disk page snapshots. These page snapshots are designed to support crash recovery, since - we may need to fix partially-written disk pages. Depending on - your system hardware and software, the risk of partial writes may + we might need to fix partially-written disk pages. Depending on + your system hardware and software, the risk of partial writes might be small enough to ignore, in which case you can significantly reduce the total volume of archived logs by turning off page snapshots using the <xref linkend="guc-full-page-writes"> @@ -1238,7 +1238,7 @@ restore_command = 'copy /mnt/server/archivedir/%f "%p"' # Windows use of the logs for PITR operations. An area for future development is to compress archived WAL data by removing unnecessary page copies even when <varname>full_page_writes</> is - on. In the meantime, administrators may wish to reduce the number + on. In the meantime, administrators might wish to reduce the number of page snapshots included in WAL by increasing the checkpoint interval parameters as much as feasible. </para> @@ -1522,7 +1522,7 @@ if (!triggered) connectivity between the two and the viability of the primary. It is also possible to use a third system (called a witness server) to avoid some problems of inappropriate failover, but the additional complexity - may not be worthwhile unless it is set-up with sufficient care and + might not be worthwhile unless it is set-up with sufficient care and rigorous testing. </para> @@ -1530,7 +1530,7 @@ if (!triggered) Once failover to the standby occurs, we have only a single server in operation. This is known as a degenerate state. The former standby is now the primary, but the former primary is down - and may stay down. To return to normal operation we must + and might stay down. To return to normal operation we must fully recreate a standby server, either on the former primary system when it comes up, or on a third, possibly new, system. Once complete the primary and standby can be @@ -1662,7 +1662,7 @@ if (!triggered) It is recommended that you use the <application>pg_dump</> and <application>pg_dumpall</> programs from the newer version of <productname>PostgreSQL</>, to take advantage of any enhancements - that may have been made in these programs. Current releases of the + that might have been made in these programs. Current releases of the dump programs can read data from any server version back to 7.0. </para> @@ -1716,7 +1716,7 @@ psql -f backup postgres <note> <para> When you <quote>move the old installation out of the way</quote> - it may no longer be perfectly usable. Some of the executable programs + it might no longer be perfectly usable. Some of the executable programs contain absolute paths to various installed programs and data files. This is usually not a big problem but if you plan on using two installations in parallel for a while you should assign them diff --git a/doc/src/sgml/bki.sgml b/doc/src/sgml/bki.sgml index 0d255c8e43..75ecc041b5 100644 --- a/doc/src/sgml/bki.sgml +++ b/doc/src/sgml/bki.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/bki.sgml,v 1.19 2006/09/16 00:30:11 momjian Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/bki.sgml,v 1.20 2007/01/31 20:56:16 momjian Exp $ --> <chapter id="bki"> <title><acronym>BKI</acronym> Backend Interface</title> @@ -29,7 +29,7 @@ </para> <para> - Related information may be found in the documentation for + Related information can be found in the documentation for <application>initdb</application>. </para> diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml index 8d64dd3ec8..f5e15f1985 100644 --- a/doc/src/sgml/catalogs.sgml +++ b/doc/src/sgml/catalogs.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/catalogs.sgml,v 2.143 2007/01/22 01:35:19 tgl Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/catalogs.sgml,v 2.144 2007/01/31 20:56:16 momjian Exp $ --> <!-- Documentation of the system catalogs, directed toward PostgreSQL developers --> @@ -523,7 +523,7 @@ The catalog <structname>pg_amop</structname> stores information about operators associated with access method operator families. There is one row for each operator that is a member of an operator family. An operator - can appear in more than one family, but may not appear in more than one + can appear in more than one family, but cannot appear in more than one position within a family. </para> @@ -870,7 +870,7 @@ <entry></entry> <entry> Always -1 in storage, but when loaded into a row descriptor - in memory this may be updated to cache the offset of the attribute + in memory this might be updated to cache the offset of the attribute within the row </entry> </row> @@ -954,7 +954,7 @@ <entry><type>bool</type></entry> <entry></entry> <entry> - This column is defined locally in the relation. Note that a column may + This column is defined locally in the relation. Note that a column can be locally defined and inherited simultaneously </entry> </row> @@ -998,7 +998,7 @@ database authorization identifiers (roles). A role subsumes the concepts of <quote>users</> and <quote>groups</>. A user is essentially just a role with the <structfield>rolcanlogin</> flag set. Any role (with or - without <structfield>rolcanlogin</>) may have other roles as members; see + without <structfield>rolcanlogin</>) can have other roles as members; see <link linkend="catalog-pg-auth-members"><structname>pg_auth_members</structname></link>. </para> @@ -1057,20 +1057,20 @@ <row> <entry><structfield>rolcreaterole</structfield></entry> <entry><type>bool</type></entry> - <entry>Role may create more roles</entry> + <entry>Role can create more roles</entry> </row> <row> <entry><structfield>rolcreatedb</structfield></entry> <entry><type>bool</type></entry> - <entry>Role may create databases</entry> + <entry>Role can create databases</entry> </row> <row> <entry><structfield>rolcatupdate</structfield></entry> <entry><type>bool</type></entry> <entry> - Role may update system catalogs directly. (Even a superuser may not do + Role can update system catalogs directly. (Even a superuser cannot do this unless this column is true) </entry> </row> @@ -1079,7 +1079,7 @@ <entry><structfield>rolcanlogin</structfield></entry> <entry><type>bool</type></entry> <entry> - Role may log in. That is, this role can be given as the initial + Role can log in. That is, this role can be given as the initial session authorization identifier </entry> </row> @@ -1177,7 +1177,7 @@ <entry><structfield>admin_option</structfield></entry> <entry><type>bool</type></entry> <entry></entry> - <entry>True if <structfield>member</> may grant membership in + <entry>True if <structfield>member</> can grant membership in <structfield>roleid</> to others</entry> </row> </tbody> @@ -1395,7 +1395,7 @@ <entry><type>char</type></entry> <entry></entry> <entry> - Indicates what contexts the cast may be invoked in. + Indicates what contexts the cast can be invoked in. <literal>e</> means only as an explicit cast (using <literal>CAST</> or <literal>::</> syntax). <literal>a</> means implicitly in assignment @@ -2245,7 +2245,7 @@ <para> In all cases, a <structname>pg_depend</structname> entry indicates that the - referenced object may not be dropped without also dropping the dependent + referenced object cannot be dropped without also dropping the dependent object. However, there are several subflavors identified by <structfield>deptype</>: @@ -2255,8 +2255,8 @@ <listitem> <para> A normal relationship between separately-created objects. The - dependent object may be dropped without affecting the - referenced object. The referenced object may only be dropped + dependent object can be dropped without affecting the + referenced object. The referenced object can only be dropped by specifying <literal>CASCADE</>, in which case the dependent object is dropped, too. Example: a table column has a normal dependency on its data type. @@ -2311,7 +2311,7 @@ </varlistentry> </variablelist> - Other dependency flavors may be needed in future. + Other dependency flavors might be needed in future. </para> </sect1> @@ -2642,7 +2642,7 @@ This is false for internal languages (such as <acronym>SQL</acronym>) and true for user-defined languages. Currently, <application>pg_dump</application> still uses this - to determine which languages need to be dumped, but this may be + to determine which languages need to be dumped, but this might be replaced by a different mechanism in the future </entry> </row> @@ -2654,7 +2654,7 @@ <entry> True if this is a trusted language, which means that it is believed not to grant access to anything outside the normal SQL execution - environment. Only superusers may create functions in untrusted + environment. Only superusers can create functions in untrusted languages </entry> </row> @@ -2748,7 +2748,7 @@ <entry><type>bytea</type></entry> <entry> Actual data stored in the large object. - This will never be more than <symbol>LOBLKSIZE</> bytes and may be less + This will never be more than <symbol>LOBLKSIZE</> bytes and might be less </entry> </row> </tbody> @@ -2759,7 +2759,7 @@ Each row of <structname>pg_largeobject</structname> holds data for one page of a large object, beginning at byte offset (<literal>pageno * LOBLKSIZE</>) within the object. The implementation - allows sparse storage: pages may be missing, and may be shorter than + allows sparse storage: pages might be missing, and might be shorter than <literal>LOBLKSIZE</> bytes even if they are not the last page of the object. Missing regions within a large object read as zeroes. </para> @@ -3439,7 +3439,7 @@ It is <literal>s</literal> for <quote>stable</> functions, whose results (for fixed inputs) do not change within a scan. It is <literal>v</literal> for <quote>volatile</> functions, - whose results may change at any time. (Use <literal>v</literal> also + whose results might change at any time. (Use <literal>v</literal> also for functions with side-effects, so that calls to them cannot get optimized away.) </entry> @@ -3754,7 +3754,7 @@ <para> In all cases, a <structname>pg_shdepend</structname> entry indicates that - the referenced object may not be dropped without also dropping the dependent + the referenced object cannot be dropped without also dropping the dependent object. However, there are several subflavors identified by <structfield>deptype</>: @@ -3796,7 +3796,7 @@ </varlistentry> </variablelist> - Other dependency flavors may be needed in future. Note in particular + Other dependency flavors might be needed in future. Note in particular that the current definition only supports roles as referenced objects. </para> @@ -3897,7 +3897,7 @@ </para> <para> - Since different kinds of statistics may be appropriate for different + Since different kinds of statistics might be appropriate for different kinds of data, <structname>pg_statistic</structname> is designed not to assume very much about what sort of statistics it stores. Only extremely general statistics (such as nullness) are given dedicated @@ -3911,7 +3911,7 @@ <para> <structname>pg_statistic</structname> should not be readable by the public, since even statistical information about a table's contents - may be considered sensitive. (Example: minimum and maximum values + might be considered sensitive. (Example: minimum and maximum values of a salary column might be quite interesting.) <link linkend="view-pg-stats"><structname>pg_stats</structname></link> is a publicly readable view on @@ -4581,7 +4581,7 @@ default expression represented by <structfield>typdefaultbin</>. If <structfield>typdefaultbin</> is null and <structfield>typdefault</> is not, then <structfield>typdefault</> is the external representation of - the type's default value, which may be fed to the type's input + the type's default value, which might be fed to the type's input converter to produce a constant </para></entry> </row> @@ -4762,7 +4762,7 @@ <para> Cursors are used internally to implement some of the components of <productname>PostgreSQL</>, such as procedural languages. - Therefore, the <structname>pg_cursors</> view may include cursors + Therefore, the <structname>pg_cursors</> view might include cursors that have not been explicitly created by the user. </para> </note> @@ -4973,7 +4973,7 @@ <para> <structname>pg_locks</structname> contains one row per active lockable object, requested lock mode, and relevant transaction. Thus, the same - lockable object may + lockable object might appear many times, if multiple transactions are holding or waiting for locks on it. However, an object that currently has no locks on it will not appear at all. @@ -5441,14 +5441,14 @@ <entry><structfield>rolcreaterole</structfield></entry> <entry><type>bool</type></entry> <entry></entry> - <entry>Role may create more roles</entry> + <entry>Role can create more roles</entry> </row> <row> <entry><structfield>rolcreatedb</structfield></entry> <entry><type>bool</type></entry> <entry></entry> - <entry>Role may create databases</entry> + <entry>Role can create databases</entry> </row> <row> @@ -5456,7 +5456,7 @@ <entry><type>bool</type></entry> <entry></entry> <entry> - Role may update system catalogs directly. (Even a superuser may not do + Role can update system catalogs directly. (Even a superuser cannot do this unless this column is true.) </entry> </row> @@ -5466,7 +5466,7 @@ <entry><type>bool</type></entry> <entry></entry> <entry> - Role may log in. That is, this role can be given as the initial + Role can log in. That is, this role can be given as the initial session authorization identifier </entry> </row> @@ -5737,7 +5737,7 @@ <entry><structfield>usecreatedb</structfield></entry> <entry><type>bool</type></entry> <entry></entry> - <entry>User may create databases</entry> + <entry>User can create databases</entry> </row> <row> @@ -5752,7 +5752,7 @@ <entry><type>bool</type></entry> <entry></entry> <entry> - User may update system catalogs. (Even a superuser may not do + User can update system catalogs. (Even a superuser cannot do this unless this column is true.) </entry> </row> @@ -6153,7 +6153,7 @@ <row> <entry><structfield>usecreatedb</structfield></entry> <entry><type>bool</type></entry> - <entry>User may create databases</entry> + <entry>User can create databases</entry> </row> <row> @@ -6166,7 +6166,7 @@ <entry><structfield>usecatupd</structfield></entry> <entry><type>bool</type></entry> <entry> - User may update system catalogs. (Even a superuser may not do + User can update system catalogs. (Even a superuser cannot do this unless this column is true.) </entry> </row> diff --git a/doc/src/sgml/charset.sgml b/doc/src/sgml/charset.sgml index 55f0c6d5c1..85252439a2 100644 --- a/doc/src/sgml/charset.sgml +++ b/doc/src/sgml/charset.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/charset.sgml,v 2.80 2007/01/09 22:22:55 momjian Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/charset.sgml,v 2.81 2007/01/31 20:56:16 momjian Exp $ --> <chapter id="charset"> <title>Localization</> @@ -155,7 +155,7 @@ initdb --locale=sv_SE environment variables seen by the server, not by the environment of any client. Therefore, be careful to configure the correct locale settings before starting the server. A consequence of this is that if - client and server are set up in different locales, messages may + client and server are set up in different locales, messages might appear in different languages depending on where they originated. </para> @@ -252,7 +252,7 @@ initdb --locale=sv_SE If locale support doesn't work in spite of the explanation above, check that the locale support in your operating system is correctly configured. To check what locales are installed on your - system, you may use the command <literal>locale -a</literal> if + system, you can use the command <literal>locale -a</literal> if your operating system provides it. </para> diff --git a/doc/src/sgml/client-auth.sgml b/doc/src/sgml/client-auth.sgml index 4b7c2c4709..8ea76a0bd0 100644 --- a/doc/src/sgml/client-auth.sgml +++ b/doc/src/sgml/client-auth.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/client-auth.sgml,v 1.96 2006/11/23 05:39:17 momjian Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/client-auth.sgml,v 1.97 2007/01/31 20:56:16 momjian Exp $ --> <chapter id="client-authentication"> <title>Client Authentication</title> @@ -48,7 +48,7 @@ runs. If all the users of a particular server also have accounts on the server's machine, it makes sense to assign database user names that match their operating system user names. However, a server that - accepts remote connections may have many database users who have no local operating system + accepts remote connections might have many database users who have no local operating system account, and in such cases there need be no connection between database user names and OS user names. </para> @@ -94,7 +94,7 @@ </para> <para> - A record may have one of the seven formats + A record can have one of the seven formats <synopsis> local <replaceable>database</replaceable> <replaceable>user</replaceable> <replaceable>auth-method</replaceable> <optional><replaceable>auth-option</replaceable></optional> host <replaceable>database</replaceable> <replaceable>user</replaceable> <replaceable>CIDR-address</replaceable> <replaceable>auth-method</replaceable> <optional><replaceable>auth-option</replaceable></optional> @@ -256,7 +256,7 @@ hostnossl <replaceable>database</replaceable> <replaceable>user</replaceable> <term><replaceable>IP-mask</replaceable></term> <listitem> <para> - These fields may be used as an alternative to the + These fields can be used as an alternative to the <replaceable>CIDR-address</replaceable> notation. Instead of specifying the mask length, the actual mask is specified in a separate column. For example, <literal>255.0.0.0</> represents an IPv4 @@ -517,7 +517,7 @@ host all all 192.168.0.0/16 ident omicron # If these are the only three lines for local connections, they will # allow local users to connect only to their own databases (databases # with the same name as their database user name) except for administrators -# and members of role "support", who may connect to all databases. The file +# and members of role "support", who can connect to all databases. The file # $PGDATA/admins contains a list of names of administrators. Passwords # are required in all cases. # @@ -559,7 +559,7 @@ local db1,db2,@demodbs all md5 <literal>trust</> authentication is appropriate and very convenient for local connections on a single-user workstation. It is usually <emphasis>not</> appropriate by itself on a multiuser - machine. However, you may be able to use <literal>trust</> even + machine. However, you might be able to use <literal>trust</> even on a multiuser machine, if you restrict access to the server's Unix-domain socket file using file-system permissions. To do this, set the <varname>unix_socket_permissions</varname> (and possibly @@ -679,7 +679,7 @@ local db1,db2,@demodbs all md5 <literal>./configure --with-krb-srvnam=whatever</>. In most environments, this parameter never needs to be changed. However, to support multiple <productname>PostgreSQL</> installations on the same host it is necessary. - Some Kerberos implementations may also require a different service name, + Some Kerberos implementations might also require a different service name, such as Microsoft Active Directory which requires the service name to be in uppercase (<literal>POSTGRES</literal>). </para> @@ -865,7 +865,7 @@ local db1,db2,@demodbs all md5 as which database user. The same <replaceable>map-name</> can be used repeatedly to specify more user-mappings within a single map. There is no restriction regarding how many database users a given - operating system user may correspond to, nor vice versa. + operating system user can correspond to, nor vice versa. </para> <para> @@ -941,7 +941,7 @@ ldap://ldap.example.net/dc=example,dc=net;EXAMPLE\ will encrypt only the connection between the PostgreSQL server and the LDAP server. The connection between the client and the PostgreSQL server is not affected by this setting. To make use of - TLS encryption, you may need to configure the LDAP library prior + TLS encryption, you might need to configure the LDAP library prior to configuring PostgreSQL. Note that encrypted LDAP is available only if the platform's LDAP library supports it. </para> @@ -1030,12 +1030,12 @@ FATAL: database "testdb" does not exist </programlisting> The database you are trying to connect to does not exist. Note that if you do not specify a database name, it defaults to the database - user name, which may or may not be the right thing. + user name, which might or might not be the right thing. </para> <tip> <para> - The server log may contain more information about an + The server log might contain more information about an authentication failure than is reported to the client. If you are confused about the reason for a failure, check the log. </para> diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml index 2a95d8fae7..2842290716 100644 --- a/doc/src/sgml/config.sgml +++ b/doc/src/sgml/config.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/config.sgml,v 1.106 2007/01/25 11:53:50 petere Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/config.sgml,v 1.107 2007/01/31 20:56:16 momjian Exp $ --> <chapter Id="runtime-config"> <title>Server Configuration</title> @@ -21,7 +21,7 @@ <para> All parameter names are case-insensitive. Every parameter takes a value of one of four types: Boolean, integer, floating point, - or string. Boolean values may be written as <literal>ON</literal>, + or string. Boolean values can be written as <literal>ON</literal>, <literal>OFF</literal>, <literal>TRUE</literal>, <literal>FALSE</literal>, <literal>YES</literal>, <literal>NO</literal>, <literal>1</literal>, <literal>0</literal> @@ -105,7 +105,7 @@ postgres -c log_connections=yes -c log_destination='syslog' <filename>postgresql.conf</filename>. Note that this means you won't be able to change the value on-the-fly by editing <filename>postgresql.conf</filename>, so while the command-line - method may be convenient, it can cost you flexibility later. + method might be convenient, it can cost you flexibility later. </para> <para> @@ -348,13 +348,13 @@ SET ENABLE_SEQSCAN TO OFF; <para> Determines the maximum number of concurrent connections to the database server. The default is typically 100 connections, but - may be less if your kernel settings will not support it (as + might be less if your kernel settings will not support it (as determined during <application>initdb</>). This parameter can only be set at server start. </para> <para> - Increasing this parameter may cause <productname>PostgreSQL</> + Increasing this parameter might cause <productname>PostgreSQL</> to request more <systemitem class="osname">System V</> shared memory or semaphores than your operating system's default configuration allows. See <xref linkend="sysvipc"> for information on how to @@ -519,7 +519,7 @@ SET ENABLE_SEQSCAN TO OFF; <listitem> <para> On systems that support the <symbol>TCP_KEEPCNT</symbol> socket option, specifies how - many keepalives may be lost before the connection is considered dead. + many keepalives can be lost before the connection is considered dead. A value of zero uses the system default. If <symbol>TCP_KEEPCNT</symbol> is not supported, this parameter must be zero. This parameter is ignored for connections made via a Unix-domain socket. @@ -704,7 +704,7 @@ SET ENABLE_SEQSCAN TO OFF; <para> Sets the amount of memory the database server uses for shared memory buffers. The default is typically 32 megabytes - (<literal>32MB</>), but may be less if your kernel settings will + (<literal>32MB</>), but might be less if your kernel settings will not support it (as determined during <application>initdb</>). This setting must be at least 128 kilobytes and at least 16 kilobytes times <xref linkend="guc-max-connections">. (Non-default @@ -716,7 +716,7 @@ SET ENABLE_SEQSCAN TO OFF; </para> <para> - Increasing this parameter may cause <productname>PostgreSQL</> + Increasing this parameter might cause <productname>PostgreSQL</> to request more <systemitem class="osname">System V</> shared memory than your operating system's default configuration allows. See <xref linkend="sysvipc"> for information on how to @@ -779,7 +779,7 @@ SET ENABLE_SEQSCAN TO OFF; </para> <para> - Increasing this parameter may cause <productname>PostgreSQL</> + Increasing this parameter might cause <productname>PostgreSQL</> to request more <systemitem class="osname">System V</> shared memory than your operating system's default configuration allows. See <xref linkend="sysvipc"> for information on how to @@ -827,7 +827,7 @@ SET ENABLE_SEQSCAN TO OFF; operations can be executed at a time by a database session, and an installation normally doesn't have many of them running concurrently, it's safe to set this value significantly larger - than <varname>work_mem</varname>. Larger settings may improve + than <varname>work_mem</varname>. Larger settings might improve performance for vacuuming and for restoring database dumps. </para> </listitem> @@ -848,7 +848,7 @@ SET ENABLE_SEQSCAN TO OFF; routine in the server, but only in key potentially-recursive routines such as expression evaluation. The default setting is two megabytes (<literal>2MB</>), which is conservatively small and - unlikely to risk crashes. However, it may be too small to allow + unlikely to risk crashes. However, it might be too small to allow execution of complex functions. Only superusers can change this setting. </para> @@ -877,7 +877,7 @@ SET ENABLE_SEQSCAN TO OFF; <para> These parameters control the size of the shared <firstterm>free space map</>, which tracks the locations of unused space in the database. - An undersized free space map may cause the database to consume + An undersized free space map can cause the database to consume increasing amounts of disk space over time, because free space that is not in the map cannot be re-used; instead <productname>PostgreSQL</> will request more disk space from the operating system when it needs @@ -889,7 +889,7 @@ SET ENABLE_SEQSCAN TO OFF; </para> <para> - Increasing these parameters may cause <productname>PostgreSQL</> + Increasing these parameters might cause <productname>PostgreSQL</> to request more <systemitem class="osname">System V</> shared memory than your operating system's default configuration allows. See <xref linkend="sysvipc"> for information on how to @@ -985,7 +985,7 @@ SET ENABLE_SEQSCAN TO OFF; <para> By preloading a shared library, the library startup time is avoided when the library is first used. However, the time to start each new - server process may increase slightly, even if that process never + server process might increase slightly, even if that process never uses the library. So this parameter is recommended only for libraries that will be used in most sessions. </para> @@ -1058,7 +1058,7 @@ SET ENABLE_SEQSCAN TO OFF; Note that on many systems, the effective resolution of sleep delays is 10 milliseconds; setting <varname>vacuum_cost_delay</varname> to a value that is - not a multiple of 10 may have the same results as setting it + not a multiple of 10 might have the same results as setting it to the next higher multiple of 10. </para> </listitem> @@ -1176,7 +1176,7 @@ SET ENABLE_SEQSCAN TO OFF; (<literal>200ms</>). Note that on many systems, the effective resolution of sleep delays is 10 milliseconds; setting <varname>bgwriter_delay</> to a value that is not a multiple of - 10 may have the same results as setting it to the next higher + 10 might have the same results as setting it to the next higher multiple of 10. This parameter can only be set in the <filename>postgresql.conf</> file or on the server command line. </para> @@ -1313,8 +1313,8 @@ SET ENABLE_SEQSCAN TO OFF; allowed to do its best in buffering, ordering, and delaying writes. This can result in significantly improved performance. However, if the system crashes, the results of the last few - committed transactions may be lost in part or whole. In the - worst case, unrecoverable data corruption may occur. + committed transactions might be lost in part or whole. In the + worst case, unrecoverable data corruption might occur. (Crashes of the database software itself are <emphasis>not</> a risk factor here. Only an operating-system-level crash creates a risk of corruption.) @@ -1419,7 +1419,7 @@ SET ENABLE_SEQSCAN TO OFF; Turning this parameter off speeds normal operation, but might lead to a corrupt database after an operating system crash or power failure. The risks are similar to turning off - <varname>fsync</>, though smaller. It may be safe to turn off + <varname>fsync</>, though smaller. It might be safe to turn off this parameter if you have hardware (such as a battery-backed disk controller) or file-system software that reduces the risk of partial page writes to an acceptably low level (e.g., ReiserFS 4). @@ -1455,7 +1455,7 @@ SET ENABLE_SEQSCAN TO OFF; </para> <para> - Increasing this parameter may cause <productname>PostgreSQL</> + Increasing this parameter might cause <productname>PostgreSQL</> to request more <systemitem class="osname">System V</> shared memory than your operating system's default configuration allows. See <xref linkend="sysvipc"> for information on how to @@ -1635,7 +1635,7 @@ archive_command = 'copy "%p" /mnt/server/archivedir/"%f"' # Windows These configuration parameters provide a crude method of influencing the query plans chosen by the query optimizer. If the default plan chosen by the optimizer for a particular query - is not optimal, a temporary solution may be found by using one + is not optimal, a temporary solution can be found by using one of these configuration parameters to force the optimizer to choose a different plan. Turning one of these settings off permanently is seldom a good idea, however. @@ -2070,7 +2070,7 @@ archive_command = 'copy "%p" /mnt/server/archivedir/"%f"' # Windows Sets the default statistics target for table columns that have not had a column-specific target set via <command>ALTER TABLE SET STATISTICS</>. Larger values increase the time needed to - do <command>ANALYZE</>, but may improve the quality of the + do <command>ANALYZE</>, but might improve the quality of the planner's estimates. The default is 10. For more information on the use of statistics by the <productname>PostgreSQL</> query planner, refer to <xref linkend="planner-stats">. @@ -2143,7 +2143,7 @@ SELECT * FROM parent WHERE key = 2400; <para> The planner will merge sub-queries into upper queries if the resulting <literal>FROM</literal> list would have no more than - this many items. Smaller values reduce planning time but may + this many items. Smaller values reduce planning time but might yield inferior query plans. The default is eight. It is usually wise to keep this less than <xref linkend="guc-geqo-threshold">. For more information see <xref linkend="explicit-joins">. @@ -2161,7 +2161,7 @@ SELECT * FROM parent WHERE key = 2400; The planner will rewrite explicit <literal>JOIN</> constructs (except <literal>FULL JOIN</>s) into lists of <literal>FROM</> items whenever a list of no more than this many items - would result. Smaller values reduce planning time but may + would result. Smaller values reduce planning time but might yield inferior query plans. </para> @@ -2172,7 +2172,7 @@ SELECT * FROM parent WHERE key = 2400; explicit <literal>JOIN</>s. Thus, the explicit join order specified in the query will be the actual order in which the relations are joined. The query planner does not always choose - the optimal join order; advanced users may elect to + the optimal join order; advanced users can elect to temporarily set this variable to 1, and then specify the join order they desire explicitly. For more information see <xref linkend="explicit-joins">. @@ -2233,7 +2233,7 @@ SELECT * FROM parent WHERE key = 2400; This method, in combination with logging to <application>stderr</>, is often more useful than logging to <application>syslog</>, since some types of messages - may not appear in <application>syslog</> output (a common example + might not appear in <application>syslog</> output (a common example is dynamic-linker failure messages). This parameter can only be set at server start. </para> @@ -2249,7 +2249,7 @@ SELECT * FROM parent WHERE key = 2400; <para> When <varname>redirect_stderr</> is enabled, this parameter determines the directory in which log files will be created. - It may be specified as an absolute path, or relative to the + It can be specified as an absolute path, or relative to the cluster data directory. This parameter can only be set in the <filename>postgresql.conf</> file or on the server command line. @@ -2353,7 +2353,7 @@ SELECT * FROM parent WHERE key = 2400; <varname>log_rotation_age</varname> to <literal>60</literal>, and <varname>log_rotation_size</varname> to <literal>1000000</literal>. Including <literal>%M</> in <varname>log_filename</varname> allows - any size-driven rotations that may occur to select a file name + any size-driven rotations that might occur to select a file name different from the hour's initial file name. </para> </listitem> @@ -2368,7 +2368,7 @@ SELECT * FROM parent WHERE key = 2400; <para> When logging to <application>syslog</> is enabled, this parameter determines the <application>syslog</application> - <quote>facility</quote> to be used. You may choose + <quote>facility</quote> to be used. You can choose from <literal>LOCAL0</>, <literal>LOCAL1</>, <literal>LOCAL2</>, <literal>LOCAL3</>, <literal>LOCAL4</>, <literal>LOCAL5</>, <literal>LOCAL6</>, <literal>LOCAL7</>; @@ -2580,7 +2580,7 @@ SELECT * FROM parent WHERE key = 2400; <term><literal>NOTICE</literal></term> <listitem> <para> - Provides information that may be helpful to users, e.g., + Provides information that might be helpful to users, e.g., truncation of long identifiers and the creation of indexes as part of primary keys. </para> @@ -3010,7 +3010,7 @@ SELECT * FROM parent WHERE key = 2400; <para> Controls whether the server should start the statistics-collection subprocess. This is on by default, but - may be turned off if you know you have no interest in + can be turned off if you know you have no interest in collecting statistics or running autovacuum. This parameter can only be set at server start, because the collection subprocess cannot be started or stopped on-the-fly. (However, the @@ -3773,7 +3773,7 @@ SET XML OPTION { DOCUMENT | CONTENT }; <listitem> <para> Sets the locale to use for formatting date and time values. - (Currently, this setting does nothing, but it may in the + (Currently, this setting does nothing, but it might in the future.) Acceptable values are system-dependent; see <xref linkend="locale"> for more information. If this variable is set to the empty string (which is the default) then the value @@ -3992,7 +3992,7 @@ dynamic_library_path = 'C:\tools\postgresql;H:\my_project\lib;$libdir' </para> <para> - Increasing this parameter may cause <productname>PostgreSQL</> + Increasing this parameter might cause <productname>PostgreSQL</> to request more <systemitem class="osname">System V</> shared memory than your operating system's default configuration allows. See <xref linkend="sysvipc"> for information on how to @@ -4167,7 +4167,7 @@ dynamic_library_path = 'C:\tools\postgresql;H:\my_project\lib;$libdir' The regular expression <quote>flavor</> can be set to <literal>advanced</>, <literal>extended</>, or <literal>basic</>. The default is <literal>advanced</>. The <literal>extended</> - setting may be useful for exact backwards compatibility with + setting might be useful for exact backwards compatibility with pre-7.4 releases of <productname>PostgreSQL</>. See <xref linkend="posix-syntax-details"> for details. </para> @@ -4207,7 +4207,7 @@ dynamic_library_path = 'C:\tools\postgresql;H:\my_project\lib;$libdir' behavior of treating backslashes as escape characters. The default will change to <literal>on</> in a future release to improve compatibility with the standard. - Applications may check this + Applications can check this parameter to determine how string literals will be processed. The presence of this parameter can also be taken as an indication that the escape string syntax (<literal>E'...'</>) is supported. @@ -4284,7 +4284,7 @@ dynamic_library_path = 'C:\tools\postgresql;H:\my_project\lib;$libdir' installed. As such, they have been excluded from the sample <filename>postgresql.conf</> file. These options report various aspects of <productname>PostgreSQL</productname> behavior - that may be of interest to certain applications, particularly + that might be of interest to certain applications, particularly administrative front-ends. </para> @@ -4677,7 +4677,7 @@ plruby.use_strict = true # generates error: unknown class name the system to instead report a warning, zero out the damaged page, and continue processing. This behavior <emphasis>will destroy data</>, namely all the rows on the damaged page. But it allows you to get - past the error and retrieve rows from any undamaged pages that may + past the error and retrieve rows from any undamaged pages that might be present in the table. So it is useful for recovering data if corruption has occurred due to hardware or software error. You should generally not set this on until you have given up hope of recovering diff --git a/doc/src/sgml/cvs.sgml b/doc/src/sgml/cvs.sgml index 254bc1e7ff..cf0f086347 100644 --- a/doc/src/sgml/cvs.sgml +++ b/doc/src/sgml/cvs.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/cvs.sgml,v 1.39 2006/11/17 05:29:46 neilc Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/cvs.sgml,v 1.40 2007/01/31 20:56:16 momjian Exp $ --> <appendix id="cvs"> <appendixinfo> @@ -88,7 +88,7 @@ cvs -z3 -d :pserver:anoncvs@anoncvs.postgresql.org:/projects/cvsroot co -P pgsql <note> <para> - If you have a fast link to the Internet, you may not need + If you have a fast link to the Internet, you might not need <option>-z3</option>, which instructs <productname>CVS</productname> to use <command>gzip</command> compression for transferred data. But on a modem-speed link, it's a very substantial win. diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml index 1446a8b0fd..5f99231c51 100644 --- a/doc/src/sgml/datatype.sgml +++ b/doc/src/sgml/datatype.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/datatype.sgml,v 1.188 2007/01/30 22:29:22 momjian Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/datatype.sgml,v 1.189 2007/01/31 20:56:16 momjian Exp $ --> <chapter id="datatype"> <title id="datatype-title">Data Types</title> @@ -14,7 +14,7 @@ <para> <productname>PostgreSQL</productname> has a rich set of native data - types available to users. Users may add new types to + types available to users. Users can add new types to <productname>PostgreSQL</productname> using the <xref linkend="sql-createtype" endterm="sql-createtype-title"> command. </para> @@ -267,7 +267,7 @@ paths, or have several possibilities for formats, such as the date and time types. Some of the input and output functions are not invertible. That is, - the result of an output function may lose accuracy when compared to + the result of an output function might lose accuracy when compared to the original input. </para> @@ -416,7 +416,7 @@ </para> <para> - The <type>bigint</type> type may not function correctly on all + The <type>bigint</type> type might not function correctly on all platforms, since it relies on compiler support for eight-byte integers. On a machine without such support, <type>bigint</type> acts the same as <type>integer</type> (but still takes up eight @@ -597,7 +597,7 @@ NUMERIC <para> Inexact means that some values cannot be converted exactly to the internal format and are stored as approximations, so that storing - and printing back out a value may show slight discrepancies. + and printing back out a value might show slight discrepancies. Managing these errors and how they propagate through calculations is the subject of an entire branch of mathematics and computer science and will not be discussed further here, except for the @@ -621,7 +621,7 @@ NUMERIC <listitem> <para> - Comparing two floating-point values for equality may or may + Comparing two floating-point values for equality might or might not work as expected. </para> </listitem> @@ -633,7 +633,7 @@ NUMERIC 1E-37 to 1E+37 with a precision of at least 6 decimal digits. The <type>double precision</type> type typically has a range of around 1E-307 to 1E+308 with a precision of at least 15 digits. Values that - are too large or too small will cause an error. Rounding may + are too large or too small will cause an error. Rounding might take place if the precision of an input number is too high. Numbers too close to zero that are not representable as distinct from zero will cause an underflow error. @@ -698,7 +698,7 @@ NUMERIC digits. The assumption that <type>real</type> and <type>double precision</type> have exactly 24 and 53 bits in the mantissa respectively is correct for IEEE-standard floating point - implementations. On non-IEEE platforms it may be off a little, but + implementations. On non-IEEE platforms it might be off a little, but for simplicity the same ranges of <replaceable>p</replaceable> are used on all platforms. </para> @@ -978,7 +978,7 @@ ALTER SEQUENCE <replaceable class="parameter">tablename</replaceable>_<replaceab The storage requirement for data of these types is 4 bytes plus the actual string, and in case of <type>character</type> plus the padding. Long strings are compressed by the system automatically, so - the physical requirement on disk may be less. Long values are also + the physical requirement on disk might be less. Long values are also stored in background tables so they do not interfere with rapid access to the shorter column values. In any case, the longest possible character string that can be stored is about 1 GB. (The @@ -1060,7 +1060,7 @@ SELECT b, char_length(b) FROM test2; terminator) but should be referenced using the constant <symbol>NAMEDATALEN</symbol>. The length is set at compile time (and is therefore adjustable for special uses); the default maximum - length may change in a future release. The type <type>"char"</type> + length might change in a future release. The type <type>"char"</type> (note the quotes) is different from <type>char(1)</type> in that it only uses one byte of storage. It is internally used in the system catalogs as a poor-man's enumeration type. @@ -1293,8 +1293,8 @@ SELECT b, char_length(b) FROM test2; <para> Depending on the front end to <productname>PostgreSQL</> you use, - you may have additional work to do in terms of escaping and - unescaping <type>bytea</type> strings. For example, you may also + you might have additional work to do in terms of escaping and + unescaping <type>bytea</type> strings. For example, you might also have to escape line feeds and carriage returns if your interface automatically translates these. </para> @@ -1436,7 +1436,7 @@ SELECT b, char_length(b) FROM test2; <para> When <type>timestamp</> values are stored as double precision floating-point numbers (currently the default), the effective limit of precision - may be less than 6. <type>timestamp</type> values are stored as seconds + might be less than 6. <type>timestamp</type> values are stored as seconds before or after midnight 2000-01-01. Microsecond precision is achieved for dates within a few years of 2000-01-01, but the precision degrades for dates further away. When <type>timestamp</type> values are stored as @@ -2166,7 +2166,7 @@ January 8 04:05:06 1999 PST <type>time</type> type can. Time zones in the real world have little meaning unless associated with a date as well as a time, - since the offset may vary through the year with daylight-saving + since the offset can vary through the year with daylight-saving time boundaries. </para> </listitem> @@ -2220,7 +2220,7 @@ January 8 04:05:06 1999 PST <para> A time zone abbreviation, for example <literal>PST</>. Such a specification merely defines a particular offset from UTC, in - contrast to full time zone names which may imply a set of daylight + contrast to full time zone names which might imply a set of daylight savings transition-date rules as well. The recognized abbreviations are listed in the <literal>pg_timezone_abbrevs</> view (see <xref linkend="view-pg-timezone-abbrevs">). You cannot set the @@ -3374,14 +3374,14 @@ SELECT * FROM pg_attribute </table> <para> - Functions coded in C (whether built-in or dynamically loaded) may be + Functions coded in C (whether built-in or dynamically loaded) can be declared to accept or return any of these pseudo data types. It is up to the function author to ensure that the function will behave safely when a pseudo-type is used as an argument type. </para> <para> - Functions coded in procedural languages may use pseudo-types only as + Functions coded in procedural languages can use pseudo-types only as allowed by their implementation languages. At present the procedural languages all forbid use of a pseudo-type as argument type, and allow only <type>void</> and <type>record</> as a result type (plus diff --git a/doc/src/sgml/datetime.sgml b/doc/src/sgml/datetime.sgml index 3d80d254f0..cbdb673b71 100644 --- a/doc/src/sgml/datetime.sgml +++ b/doc/src/sgml/datetime.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/datetime.sgml,v 2.55 2006/10/17 21:03:20 tgl Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/datetime.sgml,v 2.56 2007/01/31 20:56:16 momjian Exp $ --> <appendix id="datetime-appendix"> <title>Date/Time Support</title> @@ -7,7 +7,7 @@ <productname>PostgreSQL</productname> uses an internal heuristic parser for all date/time input support. Dates and times are input as strings, and are broken up into distinct fields with a preliminary - determination of what kind of information may be in the + determination of what kind of information can be in the field. Each field is interpreted and either assigned a numeric value, ignored, or rejected. The parser contains internal lookup tables for all textual fields, @@ -46,7 +46,7 @@ <para> If the numeric token contains a dash (<literal>-</>), slash (<literal>/</>), or two or more dots (<literal>.</>), this is - a date string which may have a text month. If a date token has + a date string which might have a text month. If a date token has already been seen, it is instead interpreted as a time zone name (e.g., <literal>America/New_York</>). </para> @@ -166,7 +166,7 @@ <tip> <para> - Gregorian years AD 1-99 may be entered by using 4 digits with leading + Gregorian years AD 1-99 can be entered by using 4 digits with leading zeros (e.g., <literal>0099</> is AD 99). </para> </tip> @@ -382,7 +382,7 @@ </para> <para> - A timezone abbreviation file may contain blank lines and comments + A timezone abbreviation file can contain blank lines and comments beginning with <literal>#</>. Non-comment lines must have one of these formats: @@ -413,7 +413,7 @@ <para> The <literal>@OVERRIDE</> syntax indicates that subsequent entries in the - file may override previous entries (i.e., entries obtained from included + file can override previous entries (i.e., entries obtained from included files). Without this, conflicting definitions of the same timezone abbreviation are considered an error. </para> diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml index 6896b7b90b..ac4d5a12b7 100644 --- a/doc/src/sgml/ddl.sgml +++ b/doc/src/sgml/ddl.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/ddl.sgml,v 1.71 2006/12/30 20:31:11 momjian Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/ddl.sgml,v 1.72 2007/01/31 20:56:16 momjian Exp $ --> <chapter id="ddl"> <title>Data Definition</title> @@ -203,10 +203,10 @@ CREATE TABLE products ( </para> <para> - The default value may be an expression, which will be + The default value can be an expression, which will be evaluated whenever the default value is inserted (<emphasis>not</emphasis> when the table is created). A common example - is that a <type>timestamp</type> column may have a default of <literal>now()</>, + is that a <type>timestamp</type> column can have a default of <literal>now()</>, so that it gets set to the time of row insertion. Another common example is generating a <quote>serial number</> for each row. In <productname>PostgreSQL</productname> this is typically done by @@ -457,7 +457,7 @@ CREATE TABLE products ( The <literal>NOT NULL</literal> constraint has an inverse: the <literal>NULL</literal> constraint. This does not mean that the column must be null, which would surely be useless. Instead, this - simply selects the default behavior that the column may be null. + simply selects the default behavior that the column might be null. The <literal>NULL</literal> constraint is not present in the SQL standard and should not be used in portable applications. (It was only added to <productname>PostgreSQL</productname> to be @@ -558,7 +558,7 @@ CREATE TABLE products ( unique constraint it is possible to store duplicate rows that contain a null value in at least one of the constrained columns. This behavior conforms to the SQL standard, but we have - heard that other SQL databases may not follow this rule. So be + heard that other SQL databases might not follow this rule. So be careful when developing applications that are intended to be portable. </para> @@ -1004,7 +1004,7 @@ CREATE TABLE order_items ( (Of course, this is only possible if the table contains fewer than 2<superscript>32</> (4 billion) rows, and in practice the table size had better be much less than that, or performance - may suffer.) + might suffer.) </para> </listitem> <listitem> @@ -1289,7 +1289,7 @@ ALTER TABLE products ALTER COLUMN price TYPE numeric(10,2); <para> <productname>PostgreSQL</> will attempt to convert the column's default value (if any) to the new type, as well as any constraints - that involve the column. But these conversions may fail, or may + that involve the column. But these conversions might fail, or might produce surprising results. It's often best to drop any constraints on the column before altering its type, and then add back suitably modified constraints afterwards. @@ -1457,9 +1457,9 @@ REVOKE ALL ON accounts FROM PUBLIC; in turn contain tables. Schemas also contain other kinds of named objects, including data types, functions, and operators. The same object name can be used in different schemas without conflict; for - example, both <literal>schema1</> and <literal>myschema</> may + example, both <literal>schema1</> and <literal>myschema</> can contain tables named <literal>mytable</>. Unlike databases, - schemas are not rigidly separated: a user may access objects in any + schemas are not rigidly separated: a user can access objects in any of the schemas in the database he is connected to, if he has privileges to do so. </para> @@ -1586,7 +1586,7 @@ CREATE SCHEMA <replaceable>schemaname</replaceable> AUTHORIZATION <replaceable>u <para> Schema names beginning with <literal>pg_</> are reserved for - system purposes and may not be created by users. + system purposes and cannot be created by users. </para> </sect2> @@ -1746,7 +1746,7 @@ SELECT 3 OPERATOR(pg_catalog.+) 4; own. To allow that, the owner of the schema needs to grant the <literal>USAGE</literal> privilege on the schema. To allow users to make use of the objects in the schema, additional privileges - may need to be granted, as appropriate for the object. + might need to be granted, as appropriate for the object. </para> <para> @@ -1786,7 +1786,7 @@ REVOKE CREATE ON SCHEMA public FROM PUBLIC; the search path. If it is not named explicitly in the path then it is implicitly searched <emphasis>before</> searching the path's schemas. This ensures that built-in names will always be - findable. However, you may explicitly place + findable. However, you can explicitly place <literal>pg_catalog</> at the end of your search path if you prefer to have user-defined names override built-in names. </para> @@ -1794,7 +1794,7 @@ REVOKE CREATE ON SCHEMA public FROM PUBLIC; <para> In <productname>PostgreSQL</productname> versions before 7.3, table names beginning with <literal>pg_</> were reserved. This is - no longer true: you may create such a table name if you wish, in + no longer true: you can create such a table name if you wish, in any non-system schema. However, it's best to continue to avoid such names, to ensure that you won't suffer a conflict if some future version defines a system table named the same as your @@ -1993,7 +1993,7 @@ SELECT name, altitude </para> <para> - In some cases you may wish to know which table a particular row + In some cases you might wish to know which table a particular row originated from. There is a system column called <structfield>tableoid</structfield> in each table which can tell you the originating table: @@ -2242,7 +2242,7 @@ VALUES ('New York', NULL, NULL, 'NY'); <listitem> <para> - Bulk loads and deletes may be accomplished by adding or removing + Bulk loads and deletes can be accomplished by adding or removing partitions, if that requirement is planned into the partitioning design. <command>ALTER TABLE</> is far faster than a bulk operation. It also entirely avoids the <command>VACUUM</command> @@ -2566,7 +2566,7 @@ DO INSTEAD <para> As we can see, a complex partitioning scheme could require a substantial amount of DDL. In the above example we would be - creating a new partition each month, so it may be wise to write a + creating a new partition each month, so it might be wise to write a script that generates the required DDL automatically. </para> @@ -2624,7 +2624,7 @@ ALTER TABLE measurement_y2003m02 NO INHERIT measurement; This allows further operations to be performed on the data before it is dropped. For example, this is often a useful time to back up the data using <command>COPY</>, <application>pg_dump</>, or - similar tools. It can also be a useful time to aggregate data + similar tools. It might also be a useful time to aggregate data into smaller formats, perform other data manipulations, or run reports. </para> diff --git a/doc/src/sgml/diskusage.sgml b/doc/src/sgml/diskusage.sgml index f1cab2a677..1399fad570 100644 --- a/doc/src/sgml/diskusage.sgml +++ b/doc/src/sgml/diskusage.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/diskusage.sgml,v 1.17 2006/09/16 00:30:12 momjian Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/diskusage.sgml,v 1.18 2007/01/31 20:56:16 momjian Exp $ --> <chapter id="diskusage"> <title>Monitoring Disk Usage</title> @@ -21,7 +21,7 @@ there is also a <acronym>TOAST</> file associated with the table, which is used to store values too wide to fit comfortably in the main table (see <xref linkend="storage-toast">). There will be one index on the - <acronym>TOAST</> table, if present. There may also be indexes associated + <acronym>TOAST</> table, if present. There might also be indexes associated with the base table. Each table and index is stored in a separate disk file — possibly more than one file, if the file would exceed one gigabyte. Naming conventions for these files are described in <xref @@ -117,9 +117,9 @@ SELECT relname, relpages FROM pg_class ORDER BY relpages DESC; <para> The most important disk monitoring task of a database administrator is to make sure the disk doesn't grow full. A filled data disk will - not result in data corruption, but it may well prevent useful activity + not result in data corruption, but it might prevent useful activity from occurring. If the disk holding the WAL files grows full, database - server panic and consequent shutdown may occur. + server panic and consequent shutdown might occur. </para> <para> diff --git a/doc/src/sgml/dml.sgml b/doc/src/sgml/dml.sgml index aed0a60a02..6c5eae9dc3 100644 --- a/doc/src/sgml/dml.sgml +++ b/doc/src/sgml/dml.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/dml.sgml,v 1.14 2006/09/18 19:54:01 tgl Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/dml.sgml,v 1.15 2007/01/31 20:56:16 momjian Exp $ --> <chapter id="dml"> <title>Data Manipulation</title> @@ -168,14 +168,14 @@ INSERT INTO products (product_no, name, price) VALUES <programlisting> UPDATE products SET price = 10 WHERE price = 5; </programlisting> - This may cause zero, one, or many rows to be updated. It is not + This might cause zero, one, or many rows to be updated. It is not an error to attempt an update that does not match any rows. </para> <para> Let's look at that command in detail. First is the key word <literal>UPDATE</literal> followed by the table name. As usual, - the table name may be schema-qualified, otherwise it is looked up + the table name can be schema-qualified, otherwise it is looked up in the path. Next is the key word <literal>SET</literal> followed by the column name, an equals sign and the new column value. The new column value can be any scalar expression, not just a constant. diff --git a/doc/src/sgml/docguide.sgml b/doc/src/sgml/docguide.sgml index d83cac5e31..8667ad0801 100644 --- a/doc/src/sgml/docguide.sgml +++ b/doc/src/sgml/docguide.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/docguide.sgml,v 1.68 2007/01/31 15:23:28 teodor Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/docguide.sgml,v 1.69 2007/01/31 20:56:17 momjian Exp $ --> <appendix id="docguide"> <title>Documentation</title> @@ -79,7 +79,7 @@ <para> The following tools are used to process the documentation. Some - may be optional, as noted. + might be optional, as noted. <variablelist> <varlistentry> @@ -168,7 +168,7 @@ <para> We have documented experience with several installation methods for the various tools that are needed to process the documentation. - These will be described below. There may be some other packaged + These will be described below. There might be some other packaged distributions for these tools. Please report package status to the documentation mailing list, and we will include that information here. @@ -673,7 +673,7 @@ save_size.pdfjadetex = 10000 It appears that current versions of the <productname>PostgreSQL</productname> documentation trigger some bug in or exceed the size limit of OpenJade. If the build process of the <acronym>RTF</acronym> version hangs for a - long time and the output file still has size 0, then you may have + long time and the output file still has size 0, then you might have hit that problem. (But keep in mind that a normal build takes 5 to 10 minutes, so don't abort too soon.) </para> @@ -1010,7 +1010,7 @@ save_size.pdfjadetex = 10000 <para> The <productname>PostgreSQL</productname> distribution includes a parsed DTD definitions file <filename>reference.ced</filename>. - You may find that when using <productname>PSGML</productname>, a + You might find that when using <productname>PSGML</productname>, a comfortable way of working with these separate files of book parts is to insert a proper <literal>DOCTYPE</literal> declaration while you're editing them. If you are working on @@ -1073,7 +1073,7 @@ save_size.pdfjadetex = 10000 <para> Reference pages that describe executable commands should contain the following sections, in this order. Sections that do not apply - may be omitted. Additional top-level sections should only be used + can be omitted. Additional top-level sections should only be used in special circumstances; often that information belongs in the <quote>Usage</quote> section. @@ -1114,7 +1114,7 @@ save_size.pdfjadetex = 10000 <listitem> <para> A list describing each command-line option. If there are a - lot of options, subsections may be used. + lot of options, subsections can be used. </para> </listitem> </varlistentry> diff --git a/doc/src/sgml/ecpg.sgml b/doc/src/sgml/ecpg.sgml index b63f45ee20..63fff1a4e2 100644 --- a/doc/src/sgml/ecpg.sgml +++ b/doc/src/sgml/ecpg.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/ecpg.sgml,v 1.77 2006/10/23 18:10:31 petere Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/ecpg.sgml,v 1.78 2007/01/31 20:56:17 momjian Exp $ --> <chapter id="ecpg"> <title><application>ECPG</application> - Embedded <acronym>SQL</acronym> in C</title> @@ -59,7 +59,7 @@ EXEC SQL ...; </programlisting> These statements syntactically take the place of a C statement. - Depending on the particular statement, they may appear at the + Depending on the particular statement, they can appear at the global level or within a function. Embedded <acronym>SQL</acronym> statements follow the case-sensitivity rules of normal <acronym>SQL</acronym> code, and not those of C. @@ -127,7 +127,7 @@ EXEC SQL CONNECT TO <replaceable>target</replaceable> <optional>AS <replaceable> (single-quoted) string literal or a variable reference. The connection target <literal>DEFAULT</literal> initiates a connection to the default database under the default user name. No separate - user name or connection name may be specified in that case. + user name or connection name can be specified in that case. </para> <para> @@ -160,7 +160,7 @@ EXEC SQL CONNECT TO <replaceable>target</replaceable> <optional>AS <replaceable> </itemizedlist> As above, the parameters <replaceable>username</replaceable> and - <replaceable>password</replaceable> may be an SQL identifier, an + <replaceable>password</replaceable> can be an SQL identifier, an SQL string literal, or a reference to a character variable. </para> @@ -694,7 +694,7 @@ EXEC SQL END DECLARE SECTION; EXEC SQL EXECUTE IMMEDIATE :stmt; </programlisting> - You may not execute statements that retrieve data (e.g., + You cannot execute statements that retrieve data (e.g., <command>SELECT</command>) this way. </para> @@ -728,7 +728,7 @@ EXEC SQL PREPARE mystmt FROM :stmt; ... EXEC SQL EXECUTE mystmt INTO v1, v2, v3 USING 37; </programlisting> - An <command>EXECUTE</command> command may have an + An <command>EXECUTE</command> command can have an <literal>INTO</literal> clause, a <literal>USING</literal> clause, both, or neither. </para> @@ -3665,7 +3665,7 @@ risnull(CINTTYPE, (char *) &i); <command>FETCH</command> statement. An SQL descriptor area groups the data of one row of data together with metadata items into one data structure. The metadata is particularly useful when executing - dynamic SQL statements, where the nature of the result columns may + dynamic SQL statements, where the nature of the result columns might not be known ahead of time. </para> @@ -4310,7 +4310,7 @@ struct <para> The statement sent to the <productname>PostgreSQL</productname> server was empty. (This cannot normally happen in an embedded - SQL program, so it may point to an internal error.) (SQLSTATE + SQL program, so it might point to an internal error.) (SQLSTATE YE002) </para> </listitem> @@ -4689,7 +4689,7 @@ cc -o myprog prog1.o prog2.o ... -lecpg <para> If you manage the build process of a larger project using - <application>make</application>, it may be convenient to include + <application>make</application>, it might be convenient to include the following implicit rule to your makefiles: <programlisting> ECPG = ecpg @@ -4949,7 +4949,7 @@ EXEC SQL OPEN <replaceable>cursor</replaceable>; <para> Here is a complete example describing the output of the - preprocessor of a file <filename>foo.pgc</filename> (details may + preprocessor of a file <filename>foo.pgc</filename> (details might change with each particular version of the preprocessor): <programlisting> EXEC SQL BEGIN DECLARE SECTION; diff --git a/doc/src/sgml/errcodes.sgml b/doc/src/sgml/errcodes.sgml index ced6197d97..7c33f11e17 100644 --- a/doc/src/sgml/errcodes.sgml +++ b/doc/src/sgml/errcodes.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/errcodes.sgml,v 1.21 2006/12/24 00:29:17 tgl Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/errcodes.sgml,v 1.22 2007/01/31 20:56:17 momjian Exp $ --> <appendix id="errcodes-appendix"> <title><productname>PostgreSQL</productname> Error Codes</title> @@ -27,7 +27,7 @@ According to the standard, the first two characters of an error code denote a class of errors, while the last three characters indicate a specific condition within that class. Thus, an application that - does not recognize the specific error code may still be able to infer + does not recognize the specific error code can still be able to infer what to do from the error class. </para> diff --git a/doc/src/sgml/extend.sgml b/doc/src/sgml/extend.sgml index 0cd07d70e1..ad22a5dcdd 100644 --- a/doc/src/sgml/extend.sgml +++ b/doc/src/sgml/extend.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/extend.sgml,v 1.32 2006/09/16 00:30:13 momjian Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/extend.sgml,v 1.33 2007/01/31 20:56:17 momjian Exp $ --> <chapter id="extend"> <title>Extending <acronym>SQL</acronym></title> @@ -145,7 +145,7 @@ <para> A domain is based on a particular base type and for many purposes - is interchangeable with its base type. However, a domain may + is interchangeable with its base type. However, a domain can have constraints that restrict its valid values to a subset of what the underlying base type would allow. </para> diff --git a/doc/src/sgml/external-projects.sgml b/doc/src/sgml/external-projects.sgml index 5ff952dfa5..6d37d92953 100644 --- a/doc/src/sgml/external-projects.sgml +++ b/doc/src/sgml/external-projects.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/external-projects.sgml,v 1.14 2006/11/20 17:42:16 neilc Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/external-projects.sgml,v 1.15 2007/01/31 20:56:17 momjian Exp $ --> <appendix id="external-projects"> <title>External Projects</title> @@ -68,7 +68,7 @@ All other language interfaces are external projects and are distributed separately. <xref linkend="language-interface-table"> includes a list of - some of these projects. Note that some of these packages may not be + some of these projects. Note that some of these packages might not be released under the same license as <productname>PostgreSQL</>. For more information on each language interface, including licensing terms, refer to its website and documentation. @@ -175,7 +175,7 @@ In addition, there are a number of procedural languages that are developed and maintained outside the core <productname>PostgreSQL</productname> distribution. <xref linkend="pl-language-table"> lists some of these - packages. Note that some of these projects may not be released under the same + packages. Note that some of these projects might not be released under the same license as <productname>PostgreSQL</>. For more information on each procedural language, including licensing information, refer to its website and documentation. diff --git a/doc/src/sgml/features.sgml b/doc/src/sgml/features.sgml index d7731a124d..26979adf52 100644 --- a/doc/src/sgml/features.sgml +++ b/doc/src/sgml/features.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/features.sgml,v 2.25 2006/09/16 00:30:13 momjian Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/features.sgml,v 2.26 2007/01/31 20:56:17 momjian Exp $ --> <appendix id="features"> <title>SQL Conformance</title> @@ -26,7 +26,7 @@ 9075 Working Group during the preparation of SQL:2003. Even so, many of the features required by SQL:2003 are already supported, though sometimes with slightly differing syntax or function. - Further moves towards conformance may be expected in later releases. + Further moves towards conformance should be expected in later releases. </para> <para> @@ -80,7 +80,7 @@ PostgreSQL supports most of the major features of SQL:2003. Out of 164 mandatory features required for full Core conformance, PostgreSQL conforms to at least 150. In addition, there is a long - list of supported optional features. It may be worth noting that at + list of supported optional features. It might be worth noting that at the time of writing, no current version of any database management system claims full conformance to Core SQL:2003. </para> @@ -90,9 +90,9 @@ that <productname>PostgreSQL</productname> supports, followed by a list of the features defined in <acronym>SQL:2003</acronym> which are not yet supported in <productname>PostgreSQL</productname>. - Both of these lists are approximate: There may be minor details that + Both of these lists are approximate: There might be minor details that are nonconforming for a feature that is listed as supported, and - large parts of an unsupported feature may in fact be implemented. + large parts of an unsupported feature might in fact be implemented. The main body of the documentation always contains the most accurate information about what does and does not work. </para> diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 02c95a6f22..a2baeb2a10 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.355 2007/01/30 22:29:22 momjian Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.356 2007/01/31 20:56:17 momjian Exp $ --> <chapter id="functions"> <title>Functions and Operators</title> @@ -324,7 +324,7 @@ <tip> <para> - Some applications may expect that + Some applications might expect that <literal><replaceable>expression</replaceable> = NULL</literal> returns true if <replaceable>expression</replaceable> evaluates to the null value. It is highly recommended that these applications @@ -582,7 +582,7 @@ data type as its argument. The functions working with <type>double precision</type> data are mostly implemented on top of the host system's C library; accuracy and behavior in - boundary cases may therefore vary depending on the host system. + boundary cases can therefore vary depending on the host system. </para> <indexterm> @@ -2804,7 +2804,7 @@ cast(-44 as bit(12)) <lineannotation>111111010100</lineannotation> other characters, the respective character in <replaceable>pattern</replaceable> must be preceded by the escape character. The default escape - character is the backslash but a different one may be selected by + character is the backslash but a different one can be selected by using the <literal>ESCAPE</literal> clause. To match the escape character itself, write two escape characters. </para> @@ -2884,7 +2884,7 @@ cast(-44 as bit(12)) <lineannotation>111111010100</lineannotation> Like <function>LIKE</function>, the <function>SIMILAR TO</function> operator succeeds only if its pattern matches the entire string; this is unlike common regular expression practice, wherein the pattern - may match any part of the string. + can match any part of the string. Also like <function>LIKE</function>, <function>SIMILAR TO</function> uses <literal>_</> and <literal>%</> as wildcard characters denoting @@ -2918,7 +2918,7 @@ cast(-44 as bit(12)) <lineannotation>111111010100</lineannotation> </listitem> <listitem> <para> - Parentheses <literal>()</literal> may be used to group items into + Parentheses <literal>()</literal> can be used to group items into a single logical item. </para> </listitem> @@ -3198,7 +3198,7 @@ regexp_replace('foobarbaz', 'b(..)', E'X\\1Y', 'g') <para> A <firstterm>constraint</> matches an empty string, but matches only when specific conditions are met. A constraint can be used where an atom - could be used, except it may not be followed by a quantifier. + could be used, except it cannot be followed by a quantifier. The simple constraints are shown in <xref linkend="posix-constraints-table">; some more constraints are described later. @@ -3276,7 +3276,7 @@ regexp_replace('foobarbaz', 'b(..)', E'X\\1Y', 'g') </table> <para> - An RE may not end with <literal>\</>. + An RE cannot end with <literal>\</>. </para> <note> @@ -3330,7 +3330,7 @@ regexp_replace('foobarbaz', 'b(..)', E'X\\1Y', 'g') <entry> <literal>{</><replaceable>m</><literal>,</><replaceable>n</><literal>}</> </entry> <entry> a sequence of <replaceable>m</> through <replaceable>n</> - (inclusive) matches of the atom; <replaceable>m</> may not exceed + (inclusive) matches of the atom; <replaceable>m</> cannot exceed <replaceable>n</> </entry> </row> @@ -3432,7 +3432,7 @@ regexp_replace('foobarbaz', 'b(..)', E'X\\1Y', 'g') </table> <para> - Lookahead constraints may not contain <firstterm>back references</> + Lookahead constraints cannot contain <firstterm>back references</> (see <xref linkend="posix-escape-sequences">), and all parentheses within them are considered non-capturing. </para> @@ -3506,7 +3506,7 @@ regexp_replace('foobarbaz', 'b(..)', E'X\\1Y', 'g') <literal>^</literal> are the members of an equivalence class, then <literal>[[=o=]]</literal>, <literal>[[=^=]]</literal>, and <literal>[o^]</literal> are all synonymous. An equivalence class - may not be an endpoint of a range. + cannot be an endpoint of a range. </para> <para> @@ -3522,7 +3522,7 @@ regexp_replace('foobarbaz', 'b(..)', E'X\\1Y', 'g') <literal>xdigit</literal>. These stand for the character classes defined in <citerefentry><refentrytitle>ctype</refentrytitle><manvolnum>3</manvolnum></citerefentry>. - A locale may provide others. A character class may not be used as + A locale can provide others. A character class cannot be used as an endpoint of a range. </para> @@ -3909,7 +3909,7 @@ regexp_replace('foobarbaz', 'b(..)', E'X\\1Y', 'g') </para> <para> - An ARE may begin with <firstterm>embedded options</>: + An ARE can begin with <firstterm>embedded options</>: a sequence <literal>(?</><replaceable>xyz</><literal>)</> (where <replaceable>xyz</> is one or more alphabetic characters) specifies options affecting the rest of the RE. @@ -4001,7 +4001,7 @@ regexp_replace('foobarbaz', 'b(..)', E'X\\1Y', 'g') <para> Embedded options take effect at the <literal>)</> terminating the sequence. - They may appear only at the start of an ARE (after the + They can appear only at the start of an ARE (after the <literal>***:</> director if any). </para> @@ -4660,7 +4660,7 @@ SELECT SUBSTRING('XY1234Z', 'Y*?([0-9]{1,3})'); </table> <para> - Certain modifiers may be applied to any template pattern to alter its + Certain modifiers can be applied to any template pattern to alter its behavior. For example, <literal>FMMonth</literal> is the <literal>Month</literal> pattern with the <literal>FM</literal> modifier. @@ -6121,7 +6121,7 @@ SELECT date_trunc('year', TIMESTAMP '2001-02-16 20:38:40'); In these expressions, the desired time zone <replaceable>zone</> can be specified either as a text string (e.g., <literal>'PST'</literal>) or as an interval (e.g., <literal>INTERVAL '-08:00'</literal>). - In the text case, a time zone name may be specified in any of the ways + In the text case, a time zone name can be specified in any of the ways described in <xref linkend="datatype-timezones">. </para> @@ -6228,7 +6228,7 @@ SELECT LOCALTIMESTAMP; <note> <para> - Other database systems may advance these values more + Other database systems might advance these values more frequently. </para> </note> @@ -6257,7 +6257,7 @@ timeofday() statement (more specifically, the time of receipt of the latest command message from the client). <function>statement_timestamp()</> and <function>transaction_timestamp()</> - return the same value during the first command of a transaction, but may + return the same value during the first command of a transaction, but might differ during subsequent commands. <function>clock_timestamp()</> returns the actual current time, and therefore its value changes even within a single SQL command. @@ -6329,7 +6329,7 @@ SELECT pg_sleep(1.5); <para> The effective resolution of the sleep interval is platform-specific; 0.01 seconds is a common value. The sleep delay will be at least as long - as specified. It may be longer depending on factors such as server load. + as specified. It might be longer depending on factors such as server load. </para> </note> @@ -6821,7 +6821,7 @@ SELECT pg_sleep(1.5); <literal>t.p</> is a <type>point</> column then <literal>SELECT p[0] FROM t</> retrieves the X coordinate and <literal>UPDATE t SET p[1] = ...</> changes the Y coordinate. - In the same way, a value of type <type>box</> or <type>lseg</> may be treated + In the same way, a value of type <type>box</> or <type>lseg</> can be treated as an array of two <type>point</> values. </para> @@ -7236,7 +7236,7 @@ nextval('foo'::text) <lineannotation><literal>foo</literal> is looked up at </programlisting> Note that late binding was the only behavior supported in <productname>PostgreSQL</productname> releases before 8.1, so you - may need to do this to preserve the semantics of old applications. + might need to do this to preserve the semantics of old applications. </para> <para> @@ -7302,7 +7302,7 @@ nextval('foo'::text) <lineannotation><literal>foo</literal> is looked up at value and sets its <literal>is_called</literal> field to <literal>true</literal>, meaning that the next <function>nextval</function> will advance the sequence before returning a value. In the three-parameter form, - <literal>is_called</literal> may be set either <literal>true</literal> or + <literal>is_called</literal> can be set either <literal>true</literal> or <literal>false</literal>. If it's set to <literal>false</literal>, the next <function>nextval</function> will return exactly the specified value, and sequence advancement commences with the following @@ -7336,7 +7336,7 @@ SELECT setval('foo', 42, false); <lineannotation>Next <function>nextval</> wi same sequence, a <function>nextval</function> operation is never rolled back; that is, once a value has been fetched it is considered used, even if the transaction that did the <function>nextval</function> later aborts. This means - that aborted transactions may leave unused <quote>holes</quote> in the + that aborted transactions might leave unused <quote>holes</quote> in the sequence of assigned values. <function>setval</function> operations are never rolled back, either. </para> @@ -8026,7 +8026,7 @@ SELECT NULLIF(value, '(none)') ... It should be noted that except for <function>count</function>, these functions return a null value when no rows are selected. In particular, <function>sum</function> of no rows returns null, not - zero as one might expect. The <function>coalesce</function> function may be + zero as one might expect. The <function>coalesce</function> function can be used to substitute zero for null when necessary. </para> @@ -8056,7 +8056,7 @@ SELECT b1 = ANY((SELECT b2 FROM t2 ...)) FROM t1 ...; <note> <para> Users accustomed to working with other SQL database management - systems may be surprised by the performance of the + systems might be surprised by the performance of the <function>count</function> aggregate when it is applied to the entire table. A query like: <programlisting> @@ -8484,7 +8484,7 @@ EXISTS (<replaceable>subquery</replaceable>) whether at least one row is returned, not all the way to completion. It is unwise to write a subquery that has any side effects (such as calling sequence functions); whether the side effects occur or not - may be difficult to predict. + might be difficult to predict. </para> <para> @@ -9296,7 +9296,7 @@ select current_date + s.a as dates from generate_series(0,14,7) as s(a); <note> <para> - The search path may be altered at run time. The command is: + The search path can be altered at run time. The command is: <programlisting> SET search_path TO <replaceable>schema</> <optional>, <replaceable>schema</>, ...</optional> </programlisting> @@ -9881,7 +9881,7 @@ SELECT pg_type_is_visible('myschema.widget'::regtype); creating command for a constraint, index, rule, or trigger. (Note that this is a decompiled reconstruction, not the original text of the command.) <function>pg_get_expr</function> decompiles the internal form of an - individual expression, such as the default value for a column. It may be + individual expression, such as the default value for a column. It can be useful when examining the contents of system catalogs. <function>pg_get_viewdef</function> reconstructs the <command>SELECT</> query that defines a view. Most of these functions come in two variants, @@ -10294,7 +10294,7 @@ postgres=# select pg_start_backup('label_goes_here'); the transaction log archive area. The history file includes the label given to <function>pg_start_backup</>, the starting and ending transaction log locations for the backup, and the starting and ending times of the backup. The return - value is the backup's ending transaction log location (which again may be of little + value is the backup's ending transaction log location (which again might be of little interest). After noting the ending location, the current transaction log insertion point is automatically advanced to the next transaction log file, so that the ending transaction log file can be archived immediately to complete the backup. @@ -10413,7 +10413,7 @@ postgres=# select * from pg_xlogfile_name_offset(pg_stop_backup()); <entry><type>bigint</type></entry> <entry> Disk space used by the table or index with the specified name. - The table name may be qualified with a schema name + The table name can be qualified with a schema name </entry> </row> <row> @@ -10454,7 +10454,7 @@ postgres=# select * from pg_xlogfile_name_offset(pg_stop_backup()); <entry><type>bigint</type></entry> <entry> Total disk space used by the table with the specified name, - including indexes and toasted data. The table name may be + including indexes and toasted data. The table name can be qualified with a schema name </entry> </row> @@ -10494,7 +10494,7 @@ postgres=# select * from pg_xlogfile_name_offset(pg_stop_backup()); The functions shown in <xref linkend="functions-admin-genfile"> provide native file access to files on the machine hosting the server. Only files within the - database cluster directory and the <varname>log_directory</> may be + database cluster directory and the <varname>log_directory</> can be accessed. Use a relative path for files within the cluster directory, and a path matching the <varname>log_directory</> configuration setting for log files. Use of these functions is restricted to superusers. @@ -10690,7 +10690,7 @@ SELECT (pg_stat_file('filename')).modification; </indexterm> <para> <function>pg_advisory_lock</> locks an application-defined resource, - which may be identified either by a single 64-bit key value or two + which can be identified either by a single 64-bit key value or two 32-bit key values (note that these two key spaces do not overlap). If another session already holds a lock on the same resource, the function will wait until the resource becomes available. The lock @@ -10796,7 +10796,7 @@ SELECT (pg_stat_file('filename')).modification; <para> The function <function>xmlcomment</function> creates an XML value containing an XML comment with the specified text as content. - The text may not contain <literal>--</literal> or end with a + The text cannot contain <literal>--</literal> or end with a <literal>-</literal> so that the resulting construct is a valid XML comment. If the argument is null, the result is null. </para> diff --git a/doc/src/sgml/gin.sgml b/doc/src/sgml/gin.sgml index 32919e5871..0a78e798f8 100644 --- a/doc/src/sgml/gin.sgml +++ b/doc/src/sgml/gin.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/gin.sgml,v 2.8 2007/01/31 15:09:45 teodor Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/gin.sgml,v 2.9 2007/01/31 20:56:17 momjian Exp $ --> <chapter id="GIN"> <title>GIN Indexes</title> @@ -15,7 +15,7 @@ <acronym>GIN</acronym> stands for Generalized Inverted Index. It is an index structure storing a set of (key, posting list) pairs, where a <quote>posting list</> is a set of rows in which the key occurs. Each - indexed value may contain many keys, so the same row ID may appear in + indexed value can contain many keys, so the same row ID can appear in multiple posting lists. </para> @@ -115,7 +115,7 @@ <listitem> <para> Returns TRUE if the indexed value satisfies the query operator with - strategy number <literal>n</> (or may satisfy, if the operator is + strategy number <literal>n</> (or would satisfy, if the operator is marked RECHECK in the operator class). The <literal>check</> array has the same length as the number of keys previously returned by <function>extractQuery</> for this query. Each element of the @@ -222,7 +222,7 @@ </para> <para> - <acronym>GIN</acronym> searches keys only by equality matching. This may + <acronym>GIN</acronym> searches keys only by equality matching. This might be improved in future. </para> </sect1> diff --git a/doc/src/sgml/gist.sgml b/doc/src/sgml/gist.sgml index 2418c72aa2..a02da6a9f6 100644 --- a/doc/src/sgml/gist.sgml +++ b/doc/src/sgml/gist.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/gist.sgml,v 1.27 2006/10/23 18:10:31 petere Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/gist.sgml,v 1.28 2007/01/31 20:56:17 momjian Exp $ --> <chapter id="GiST"> <title>GiST Indexes</title> @@ -248,7 +248,7 @@ Usually, replay of the WAL log is sufficient to restore the integrity of a GiST index following a database crash. However, there are some corner cases in which the index state is not fully rebuilt. The index - will still be functionally correct, but there may be some performance + will still be functionally correct, but there might be some performance degradation. When this occurs, the index can be repaired by <command>VACUUM</>ing its table, or by rebuilding the index using <command>REINDEX</>. In some cases a plain <command>VACUUM</> is diff --git a/doc/src/sgml/indexam.sgml b/doc/src/sgml/indexam.sgml index f8f3f1cc76..d559be0b6e 100644 --- a/doc/src/sgml/indexam.sgml +++ b/doc/src/sgml/indexam.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/indexam.sgml,v 2.20 2007/01/20 23:13:01 tgl Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/indexam.sgml,v 2.21 2007/01/31 20:56:17 momjian Exp $ --> <chapter id="indexam"> <title>Index Access Method Interface Definition</title> @@ -33,7 +33,7 @@ block number and an item number within that block (see <xref linkend="storage-page-layout">). This is sufficient information to fetch a particular row version from the table. - Indexes are not directly aware that under MVCC, there may be multiple + Indexes are not directly aware that under MVCC, there might be multiple extant versions of the same logical row; to an index, each tuple is an independent object that needs its own index entry. Thus, an update of a row always creates all-new index entries for the row, even if @@ -174,7 +174,7 @@ aminsert (Relation indexRelation, <literal>heap_tid</> is the TID to be indexed. If the access method supports unique indexes (its <structname>pg_am</>.<structfield>amcanunique</> flag is true) then - <literal>check_uniqueness</> may be true, in which case the access method + <literal>check_uniqueness</> might be true, in which case the access method must verify that there is no conflicting row; this is the only situation in which the access method normally needs the <literal>heapRelation</> parameter. See <xref linkend="index-unique-checks"> for details. @@ -205,7 +205,7 @@ ambulkdelete (IndexVacuumInfo *info, <para> Because of limited <varname>maintenance_work_mem</>, - <function>ambulkdelete</> may need to be called more than once when many + <function>ambulkdelete</> might need to be called more than once when many tuples are to be deleted. The <literal>stats</> argument is the result of the previous call for this index (it is NULL for the first call within a <command>VACUUM</> operation). This allows the AM to accumulate statistics @@ -222,7 +222,7 @@ amvacuumcleanup (IndexVacuumInfo *info, </programlisting> Clean up after a <command>VACUUM</command> operation (zero or more <function>ambulkdelete</> calls). This does not have to do anything - beyond returning index statistics, but it may perform bulk cleanup + beyond returning index statistics, but it might perform bulk cleanup such as reclaiming empty index pages. <literal>stats</> is whatever the last <function>ambulkdelete</> call returned, or NULL if <function>ambulkdelete</> was not called because no tuples needed to be @@ -418,7 +418,7 @@ amrestrpos (IndexScanDesc scan); </para> <para> - The operator family may indicate that the index is <firstterm>lossy</> for a + The operator family can indicate that the index is <firstterm>lossy</> for a particular operator; this implies that the index scan will return all the entries that pass the scan key, plus possibly additional entries that do not. The core system's index-scan machinery will then apply that operator @@ -467,7 +467,7 @@ amrestrpos (IndexScanDesc scan); <para> The access method must support <quote>marking</> a position in a scan - and later returning to the marked position. The same position may be + and later returning to the marked position. The same position might be restored multiple times. However, only one position need be remembered per scan; a new <function>ammarkpos</> call overrides the previously marked position. @@ -480,7 +480,7 @@ amrestrpos (IndexScanDesc scan); would have found the entry if it had existed when the scan started, or for the scan to return such an entry upon rescanning or backing up even though it had not been returned the first time through. Similarly, - a concurrent delete may or may not be reflected in the results of a scan. + a concurrent delete might or might not be reflected in the results of a scan. What is important is that insertions or deletions not cause the scan to miss or multiply return entries that were not themselves being inserted or deleted. @@ -518,7 +518,7 @@ amrestrpos (IndexScanDesc scan); <literal>RowExclusiveLock</> when updating the index (including plain <command>VACUUM</>). Since these lock types do not conflict, the access method is responsible for handling any - fine-grained locking it may need. An exclusive lock on the index as a whole + fine-grained locking it might need. An exclusive lock on the index as a whole will be taken only during index creation, destruction, <command>REINDEX</>, or <command>VACUUM FULL</>. </para> @@ -537,7 +537,7 @@ amrestrpos (IndexScanDesc scan); <firstterm>heap</>) and the index. Because <productname>PostgreSQL</productname> separates accesses and updates of the heap from those of the index, there are windows in - which the index may be inconsistent with the heap. We handle this problem + which the index might be inconsistent with the heap. We handle this problem with the following rules: <itemizedlist> @@ -582,7 +582,7 @@ amrestrpos (IndexScanDesc scan); against this scenario by requiring the scan keys to be rechecked against the heap row in all cases, but that is too expensive. Instead, we use a pin on an index page as a proxy to indicate that the reader - may still be <quote>in flight</> from the index entry to the matching + might still be <quote>in flight</> from the index entry to the matching heap entry. Making <function>ambulkdelete</> block on such a pin ensures that <command>VACUUM</> cannot delete the heap entry before the reader is done with it. This solution costs little in run time, and adds blocking @@ -595,7 +595,7 @@ amrestrpos (IndexScanDesc scan); entry. This is expensive for a number of reasons. An <quote>asynchronous</> scan in which we collect many TIDs from the index, and only visit the heap tuples sometime later, requires much less index - locking overhead and may allow a more efficient heap access pattern. + locking overhead and can allow a more efficient heap access pattern. Per the above analysis, we must use the synchronous approach for non-MVCC-compliant snapshots, but an asynchronous scan is workable for a query using an MVCC snapshot. diff --git a/doc/src/sgml/indices.sgml b/doc/src/sgml/indices.sgml index 6ff9c4d4b4..95b4134b17 100644 --- a/doc/src/sgml/indices.sgml +++ b/doc/src/sgml/indices.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/indices.sgml,v 1.67 2006/12/23 00:43:08 tgl Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/indices.sgml,v 1.68 2007/01/31 20:56:17 momjian Exp $ --> <chapter id="indexes"> <title id="indexes-title">Indexes</title> @@ -74,12 +74,12 @@ CREATE INDEX test1_id_index ON test1 (id); Once an index is created, no further intervention is required: the system will update the index when the table is modified, and it will use the index in queries when it thinks this would be more efficient - than a sequential table scan. But you may have to run the + than a sequential table scan. But you might have to run the <command>ANALYZE</command> command regularly to update statistics to allow the query planner to make educated decisions. See <xref linkend="performance-tips"> for information about how to find out whether an index is used and when and why the - planner may choose <emphasis>not</emphasis> to use an index. + planner might choose <emphasis>not</emphasis> to use an index. </para> <para> @@ -193,7 +193,7 @@ CREATE INDEX <replaceable>name</replaceable> ON <replaceable>table</replaceable> indexes to perform no better than B-tree indexes, and the index size and build time for hash indexes is much worse. Furthermore, hash index operations are not presently WAL-logged, - so hash indexes may need to be rebuilt with <command>REINDEX</> + so hash indexes might need to be rebuilt with <command>REINDEX</> after a database crash. For these reasons, hash index use is presently discouraged. </para> @@ -296,7 +296,7 @@ CREATE TABLE test2 ( <programlisting> SELECT name FROM test2 WHERE major = <replaceable>constant</replaceable> AND minor = <replaceable>constant</replaceable>; </programlisting> - then it may be appropriate to define an index on the columns + then it might be appropriate to define an index on the columns <structfield>major</structfield> and <structfield>minor</structfield> together, e.g., <programlisting> @@ -306,7 +306,7 @@ CREATE INDEX test2_mm_idx ON test2 (major, minor); <para> Currently, only the B-tree and GiST index types support multicolumn - indexes. Up to 32 columns may be specified. (This limit can be + indexes. Up to 32 columns can be specified. (This limit can be altered when building <productname>PostgreSQL</productname>; see the file <filename>pg_config_manual.h</filename>.) </para> @@ -413,7 +413,7 @@ CREATE INDEX test2_mm_idx ON test2 (major, minor); <para> In all but the simplest applications, there are various combinations of - indexes that may be useful, and the database developer must make + indexes that might be useful, and the database developer must make trade-offs to decide which indexes to provide. Sometimes multicolumn indexes are best, but sometimes it's better to create separate indexes and rely on the index-combination feature. For example, if your @@ -450,7 +450,7 @@ CREATE INDEX test2_mm_idx ON test2 (major, minor); </indexterm> <para> - Indexes may also be used to enforce uniqueness of a column's value, + Indexes can also be used to enforce uniqueness of a column's value, or the uniqueness of the combined values of more than one column. <synopsis> CREATE UNIQUE INDEX <replaceable>name</replaceable> ON <replaceable>table</replaceable> (<replaceable>column</replaceable> <optional>, ...</optional>); @@ -538,7 +538,7 @@ CREATE INDEX people_names ON people ((first_name || ' ' || last_name)); <para> The syntax of the <command>CREATE INDEX</> command normally requires writing parentheses around index expressions, as shown in the second - example. The parentheses may be omitted when the expression is just + example. The parentheses can be omitted when the expression is just a function call, as in the first example. </para> @@ -687,7 +687,7 @@ SELECT * FROM orders WHERE billed is not true AND amount > 5000.00; <programlisting> SELECT * FROM orders WHERE order_nr = 3501; </programlisting> - The order 3501 may be among the billed or among the unbilled + The order 3501 might be among the billed or among the unbilled orders. </para> </example> @@ -755,8 +755,8 @@ CREATE UNIQUE INDEX tests_success_constraint ON tests (subject, target) <para> Finally, a partial index can also be used to override the system's - query plan choices. It may occur that data sets with peculiar - distributions will cause the system to use an index when it really + query plan choices. Also, data sets with peculiar + distributions might cause the system to use an index when it really should not. In that case the index can be set up so that it is not available for the offending query. Normally, <productname>PostgreSQL</> makes reasonable choices about index @@ -795,7 +795,7 @@ CREATE UNIQUE INDEX tests_success_constraint ON tests (subject, target) </indexterm> <para> - An index definition may specify an <firstterm>operator + An index definition can specify an <firstterm>operator class</firstterm> for each column of an index. <synopsis> CREATE INDEX <replaceable>name</replaceable> ON <replaceable>table</replaceable> (<replaceable>column</replaceable> <replaceable>opclass</replaceable> <optional>, ...</optional>); @@ -994,15 +994,15 @@ SELECT am.amname AS index_method, via run-time parameters (described in <xref linkend="runtime-config-query-constants">). An inaccurate selectivity estimate is due to - insufficient statistics. It may be possible to improve this by + insufficient statistics. It might be possible to improve this by tuning the statistics-gathering parameters (see <xref linkend="sql-altertable" endterm="sql-altertable-title">). </para> <para> If you do not succeed in adjusting the costs to be more - appropriate, then you may have to resort to forcing index usage - explicitly. You may also want to contact the + appropriate, then you might have to resort to forcing index usage + explicitly. You might also want to contact the <productname>PostgreSQL</> developers to examine the issue. </para> </listitem> diff --git a/doc/src/sgml/information_schema.sgml b/doc/src/sgml/information_schema.sgml index 58cde10f06..9fcdbdf18e 100644 --- a/doc/src/sgml/information_schema.sgml +++ b/doc/src/sgml/information_schema.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/information_schema.sgml,v 1.29 2006/10/23 18:10:31 petere Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/information_schema.sgml,v 1.30 2007/01/31 20:56:17 momjian Exp $ --> <chapter id="information-schema"> <title>The Information Schema</title> @@ -170,7 +170,7 @@ <entry><literal>grantee</literal></entry> <entry><type>sql_identifier</type></entry> <entry> - Name of the role to which this role membership was granted (may + Name of the role to which this role membership was granted (can be the current user, or a different role in case of nested role memberships) </entry> @@ -222,7 +222,7 @@ <entry><literal>grantee</literal></entry> <entry><type>sql_identifier</type></entry> <entry> - Name of the role to which this role membership was granted (may + Name of the role to which this role membership was granted (can be the current user, or a different role in case of nested role memberships) </entry> @@ -357,7 +357,7 @@ If <literal>data_type</literal> identifies a numeric type, this column contains the (declared or implicit) precision of the type for this attribute. The precision indicates the number of - significant digits. It may be expressed in decimal (base 10) + significant digits. It can be expressed in decimal (base 10) or binary (base 2) terms, as specified in the column <literal>numeric_precision_radix</literal>. For all other data types, this column is null. @@ -383,7 +383,7 @@ If <literal>data_type</literal> identifies an exact numeric type, this column contains the (declared or implicit) scale of the type for this attribute. The scale indicates the number of - significant digits to the right of the decimal point. It may + significant digits to the right of the decimal point. It can be expressed in decimal (base 10) or binary (base 2) terms, as specified in the column <literal>numeric_precision_radix</literal>. For all other data @@ -916,7 +916,7 @@ <literal>YES</literal> if the column is possibly nullable, <literal>NO</literal> if it is known not nullable. A not-null constraint is one way a column can be known not nullable, but - there may be others. + there can be others. </entry> </row> @@ -964,7 +964,7 @@ If <literal>data_type</literal> identifies a numeric type, this column contains the (declared or implicit) precision of the type for this column. The precision indicates the number of - significant digits. It may be expressed in decimal (base 10) + significant digits. It can be expressed in decimal (base 10) or binary (base 2) terms, as specified in the column <literal>numeric_precision_radix</literal>. For all other data types, this column is null. @@ -990,7 +990,7 @@ If <literal>data_type</literal> identifies an exact numeric type, this column contains the (declared or implicit) scale of the type for this column. The scale indicates the number of - significant digits to the right of the decimal point. It may + significant digits to the right of the decimal point. It can be expressed in decimal (base 10) or binary (base 2) terms, as specified in the column <literal>numeric_precision_radix</literal>. For all other data @@ -1227,7 +1227,7 @@ is supposed to identify the underlying built-in type of the column. In <productname>PostgreSQL</productname>, this means that the type is defined in the system catalog schema - <literal>pg_catalog</literal>. This column may be useful if the + <literal>pg_catalog</literal>. This column might be useful if the application can handle the well-known built-in types specially (for example, format the numeric types differently or use the data in the precision columns). The columns <literal>udt_name</literal>, @@ -1738,7 +1738,7 @@ If the domain has a numeric type, this column contains the (declared or implicit) precision of the type for this column. The precision indicates the number of significant digits. It - may be expressed in decimal (base 10) or binary (base 2) terms, + can be expressed in decimal (base 10) or binary (base 2) terms, as specified in the column <literal>numeric_precision_radix</literal>. For all other data types, this column is null. @@ -1764,7 +1764,7 @@ If the domain has an exact numeric type, this column contains the (declared or implicit) scale of the type for this column. The scale indicates the number of significant digits to the - right of the decimal point. It may be expressed in decimal + right of the decimal point. It can be expressed in decimal (base 10) or binary (base 2) terms, as specified in the column <literal>numeric_precision_radix</literal>. For all other data types, this column is null. @@ -2126,7 +2126,7 @@ ORDER BY c.ordinal_position; <para> For permission checking, the set of <quote>applicable roles</quote> - is applied, which may be broader than the set of enabled roles. So + is applied, which can be broader than the set of enabled roles. So generally, it is better to use the view <literal>applicable_roles</literal> instead of this one; see also there. @@ -2753,7 +2753,7 @@ ORDER BY c.ordinal_position; <row> <entry><literal>routine_name</literal></entry> <entry><type>sql_identifier</type></entry> - <entry>Name of the function (may be duplicated in case of overloading)</entry> + <entry>Name of the function (might be duplicated in case of overloading)</entry> </row> <row> @@ -2863,7 +2863,7 @@ ORDER BY c.ordinal_position; applies to domains, and since domains do not have real privileges in <productname>PostgreSQL</productname>, this view is empty. Further information can be found under - <literal>usage_privileges</literal>. In the future, this view may + <literal>usage_privileges</literal>. In the future, this view might contain more useful information. </para> @@ -3003,7 +3003,7 @@ ORDER BY c.ordinal_position; <row> <entry><literal>routine_name</literal></entry> <entry><type>sql_identifier</type></entry> - <entry>Name of the function (may be duplicated in case of overloading)</entry> + <entry>Name of the function (might be duplicated in case of overloading)</entry> </row> <row> @@ -3084,7 +3084,7 @@ ORDER BY c.ordinal_position; <row> <entry><literal>routine_name</literal></entry> <entry><type>sql_identifier</type></entry> - <entry>Name of the function (may be duplicated in case of overloading)</entry> + <entry>Name of the function (might be duplicated in case of overloading)</entry> </row> <row> @@ -3737,7 +3737,7 @@ ORDER BY c.ordinal_position; <entry> This column contains the (declared or implicit) precision of the sequence data type (see above). The precision indicates - the number of significant digits. It may be expressed in + the number of significant digits. It can be expressed in decimal (base 10) or binary (base 2) terms, as specified in the column <literal>numeric_precision_radix</literal>. </entry> @@ -3761,7 +3761,7 @@ ORDER BY c.ordinal_position; This column contains the (declared or implicit) scale of the sequence data type (see above). The scale indicates the number of significant digits to the right of the decimal point. It - may be expressed in decimal (base 10) or binary (base 2) terms, + can be expressed in decimal (base 10) or binary (base 2) terms, as specified in the column <literal>numeric_precision_radix</literal>. </entry> @@ -4700,7 +4700,7 @@ ORDER BY c.ordinal_position; incompatibilities with the SQL standard that affect the representation in the information schema. First, trigger names are local to the table in <productname>PostgreSQL</productname>, rather - than being independent schema objects. Therefore there may be duplicate + than being independent schema objects. Therefore there can be duplicate trigger names defined in one schema, as long as they belong to different tables. (<literal>trigger_catalog</literal> and <literal>trigger_schema</literal> are really the values pertaining @@ -4734,7 +4734,7 @@ ORDER BY c.ordinal_position; in <productname>PostgreSQL</productname>, this view shows implicit <literal>USAGE</literal> privileges granted to <literal>PUBLIC</literal> for all domains. In the future, this - view may contain more useful information. + view might contain more useful information. </para> <table> diff --git a/doc/src/sgml/installation.sgml b/doc/src/sgml/installation.sgml index b07e694fff..a728bbac5a 100644 --- a/doc/src/sgml/installation.sgml +++ b/doc/src/sgml/installation.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/installation.sgml,v 1.278 2007/01/29 21:49:17 momjian Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/installation.sgml,v 1.279 2007/01/31 20:56:17 momjian Exp $ --> <chapter id="installation"> <title><![%standalone-include[<productname>PostgreSQL</>]]> @@ -1027,7 +1027,7 @@ su - postgres executables considerably, and on non-GCC compilers it usually also disables compiler optimization, causing slowdowns. However, having the symbols available is extremely helpful for dealing - with any problems that may arise. Currently, this option is + with any problems that might arise. Currently, this option is recommended for production installations only if you use GCC. But you should always have it on if you are doing development work or running a beta version. @@ -1414,7 +1414,7 @@ All of PostgreSQL is successfully made. Ready to install. investigates (for example, software upgrades), then it's a good idea to do <command>gmake distclean</> before reconfiguring and rebuilding. Without this, your changes in configuration choices - may not propagate everywhere they need to. + might not propagate everywhere they need to. </para> </sect1> @@ -1636,7 +1636,7 @@ nohup /usr/local/pgsql/bin/postgres -D /usr/local/pgsql/data \ </para> <para> - To stop a server running in the background you can type + To stop a server running in the background you can type: <programlisting> kill `cat /usr/local/pgsql/data/postmaster.pid` </programlisting> diff --git a/doc/src/sgml/intro.sgml b/doc/src/sgml/intro.sgml index f15caba0aa..78e8013d66 100644 --- a/doc/src/sgml/intro.sgml +++ b/doc/src/sgml/intro.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/intro.sgml,v 1.31 2006/03/10 19:10:48 momjian Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/intro.sgml,v 1.32 2007/01/31 20:56:17 momjian Exp $ --> <preface id="preface"> <title>Preface</title> @@ -74,7 +74,7 @@ <listitem> <para> - <xref linkend="internals"> contains assorted information that may be of + <xref linkend="internals"> contains assorted information that might be of use to <productname>PostgreSQL</> developers. </para> </listitem> diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml index d7b32f9a23..79ea530381 100644 --- a/doc/src/sgml/libpq.sgml +++ b/doc/src/sgml/libpq.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/libpq.sgml,v 1.222 2007/01/30 22:29:22 momjian Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/libpq.sgml,v 1.223 2007/01/31 20:56:17 momjian Exp $ --> <chapter id="libpq"> <title><application>libpq</application> - C Library</title> @@ -130,7 +130,7 @@ PGconn *PQconnectdb(const char *conninfo); </para> <para> Using <literal>hostaddr</> instead of <literal>host</> allows the - application to avoid a host name look-up, which may be important in + application to avoid a host name look-up, which might be important in applications with time constraints. However, Kerberos authentication requires the host name. The following therefore applies: If <literal>host</> is specified without <literal>hostaddr</>, a host name @@ -429,7 +429,7 @@ PostgresPollingStatusType PQconnectPoll(PGconn *conn); </para> <para> If <function>PQconnectStart</> succeeds, the next stage is to poll - <application>libpq</> so that it may proceed with the connection sequence. + <application>libpq</> so that it can proceed with the connection sequence. Use <function>PQsocket(conn)</function> to obtain the descriptor of the socket underlying the database connection. Loop thus: If <function>PQconnectPoll(conn)</function> last returned @@ -451,13 +451,13 @@ PostgresPollingStatusType PQconnectPoll(PGconn *conn); </para> <para> - At any time during connection, the status of the connection may be + At any time during connection, the status of the connection can be checked by calling <function>PQstatus</>. If this gives <symbol>CONNECTION_BAD</>, then the connection procedure has failed; if it gives <function>CONNECTION_OK</>, then the connection is ready. Both of these states are equally detectable - from the return value of <function>PQconnectPoll</>, described above. Other states may also occur + from the return value of <function>PQconnectPoll</>, described above. Other states might also occur during (and only during) an asynchronous connection procedure. These - indicate the current stage of the connection procedure and may be useful + indicate the current stage of the connection procedure and might be useful to provide feedback to the user for example. These statuses are: <variablelist> @@ -583,7 +583,7 @@ typedef struct </para> <para> - Returns a connection options array. This may be used to determine + Returns a connection options array. This can be used to determine all possible <function>PQconnectdb</function> options and their current default values. The return value points to an array of <structname>PQconninfoOption</structname> structures, which ends @@ -638,7 +638,7 @@ void PQreset(PGconn *conn); This function will close the connection to the server and attempt to reestablish a new connection to the same server, using all the same - parameters previously used. This may be useful for + parameters previously used. This might be useful for error recovery if a working connection is lost. </para> </listitem> @@ -661,7 +661,7 @@ PostgresPollingStatusType PQresetPoll(PGconn *conn); <para> These functions will close the connection to the server and attempt to reestablish a new connection to the same server, using all the same - parameters previously used. This may be useful for error recovery if a + parameters previously used. This can be useful for error recovery if a working connection is lost. They differ from <function>PQreset</function> (above) in that they act in a nonblocking manner. These functions suffer from the same restrictions as <function>PQconnectStart</> and <function>PQconnectPoll</>. @@ -682,7 +682,7 @@ PostgresPollingStatusType PQresetPoll(PGconn *conn); <title>Connection Status Functions</title> <para> - These functions may be used to interrogate the status + These functions can be used to interrogate the status of an existing database connection object. </para> @@ -916,9 +916,9 @@ in a numeric form that is much easier to compare against. <para> If no value for <literal>standard_conforming_strings</> is reported, -applications may assume it is <literal>off</>, that is, backslashes +applications can assume it is <literal>off</>, that is, backslashes are treated as escapes in string literals. Also, the presence of this -parameter may be taken as an indication that the escape string syntax +parameter can be taken as an indication that the escape string syntax (<literal>E'...'</>) is accepted. </para> @@ -938,7 +938,7 @@ It is unwise to assume the pointer will remain valid across queries. <synopsis> int PQprotocolVersion(const PGconn *conn); </synopsis> -Applications may wish to use this to determine whether certain features +Applications might wish to use this to determine whether certain features are supported. Currently, the possible values are 2 (2.0 protocol), 3 (3.0 protocol), or zero (connection bad). This will not change after connection @@ -958,7 +958,7 @@ only protocol 2.0. (Protocol 1.0 is obsolete and not supported by <application> <synopsis> int PQserverVersion(const PGconn *conn); </synopsis> -Applications may use this to determine the version of the database server they +Applications might use this to determine the version of the database server they are connected to. The number is formed by converting the major, minor, and revision numbers into two-decimal-digit numbers and appending them together. For example, version 8.1.5 will be returned as 80105, and version @@ -1174,7 +1174,7 @@ The function arguments are: The number of parameters supplied; it is the length of the arrays <parameter>paramTypes[]</>, <parameter>paramValues[]</>, <parameter>paramLengths[]</>, and <parameter>paramFormats[]</>. (The - array pointers may be <symbol>NULL</symbol> when <parameter>nParams</> + array pointers can be <symbol>NULL</symbol> when <parameter>nParams</> is zero.) </para> </listitem> @@ -1212,7 +1212,7 @@ The function arguments are: <para> Specifies the actual data lengths of binary-format parameters. It is ignored for null parameters and text-format parameters. - The array pointer may be null when there are no binary parameters. + The array pointer can be null when there are no binary parameters. </para> </listitem> </varlistentry> @@ -1249,7 +1249,7 @@ The function arguments are: <para> The primary advantage of <function>PQexecParams</> over <function>PQexec</> -is that parameter values may be separated from the command string, thus +is that parameter values can be separated from the command string, thus avoiding the need for tedious and error-prone quoting and escaping. </para> @@ -1310,7 +1310,7 @@ connections; it will fail when using protocol 2.0. <para> The function creates a prepared statement named <parameter>stmtName</> from the <parameter>query</> string, which must contain a single SQL command. -<parameter>stmtName</> may be <literal>""</> to create an unnamed statement, +<parameter>stmtName</> can be <literal>""</> to create an unnamed statement, in which case any pre-existing unnamed statement is automatically replaced; otherwise it is an error if the statement name is already defined in the current session. @@ -1318,12 +1318,12 @@ If any parameters are used, they are referred to in the query as <literal>$1</>, <literal>$2</>, etc. <parameter>nParams</> is the number of parameters for which types are pre-specified in the array <parameter>paramTypes[]</>. (The array pointer -may be <symbol>NULL</symbol> when <parameter>nParams</> is zero.) +can be <symbol>NULL</symbol> when <parameter>nParams</> is zero.) <parameter>paramTypes[]</> specifies, by OID, the data types to be assigned to the parameter symbols. If <parameter>paramTypes</> is <symbol>NULL</symbol>, or any particular element in the array is zero, the server assigns a data type to the parameter symbol in the same way it would do for an untyped literal -string. Also, the query may use parameter symbols with numbers higher than +string. Also, the query can use parameter symbols with numbers higher than <parameter>nParams</>; data types will be inferred for these symbols as well. (See <function>PQdescribePrepared</function> for a means to find out what data types were inferred.) @@ -1410,12 +1410,12 @@ connections; it will fail when using protocol 2.0. </para> <para> -<parameter>stmtName</> may be <literal>""</> or NULL to reference the unnamed +<parameter>stmtName</> can be <literal>""</> or NULL to reference the unnamed statement, otherwise it must be the name of an existing prepared statement. On success, a <structname>PGresult</> with status <literal>PGRES_COMMAND_OK</literal> is returned. The functions <function>PQnparams</function> and <function>PQparamtype</function> -may be applied to this <structname>PGresult</> to obtain information +can be applied to this <structname>PGresult</> to obtain information about the parameters of the prepared statement, and the functions <function>PQnfields</function>, <function>PQfname</function>, <function>PQftype</function>, etc provide information about the result @@ -1445,12 +1445,12 @@ connections; it will fail when using protocol 2.0. </para> <para> -<parameter>portalName</> may be <literal>""</> or NULL to reference the unnamed +<parameter>portalName</> can be <literal>""</> or NULL to reference the unnamed portal, otherwise it must be the name of an existing portal. On success, a <structname>PGresult</> with status <literal>PGRES_COMMAND_OK</literal> is returned. The functions <function>PQnfields</function>, <function>PQfname</function>, -<function>PQftype</function>, etc may be applied to the +<function>PQftype</function>, etc can be applied to the <structname>PGresult</> to obtain information about the result columns (if any) of the portal. </para> @@ -1549,7 +1549,7 @@ the query. Note that a <command>SELECT</command> command that happens to retrieve zero rows still shows <literal>PGRES_TUPLES_OK</literal>. <literal>PGRES_COMMAND_OK</literal> is for commands that can never return rows (<command>INSERT</command>, <command>UPDATE</command>, -etc.). A response of <literal>PGRES_EMPTY_QUERY</literal> may indicate +etc.). A response of <literal>PGRES_EMPTY_QUERY</literal> might indicate a bug in the client software. </para> @@ -1673,7 +1673,7 @@ present. <listitem> <para> Detail: an optional secondary error message carrying more detail about -the problem. May run to multiple lines. +the problem. Might run to multiple lines. </para> </listitem> </varlistentry> @@ -1684,7 +1684,7 @@ the problem. May run to multiple lines. <para> Hint: an optional suggestion what to do about the problem. This is intended to differ from detail in that it offers advice (potentially -inappropriate) rather than hard facts. May run to multiple lines. +inappropriate) rather than hard facts. Might run to multiple lines. </para> </listitem> </varlistentry> @@ -2278,7 +2278,7 @@ char *PQcmdStatus(PGresult *res); </synopsis> </para> <para> -Commonly this is just the name of the command, but it may include additional +Commonly this is just the name of the command, but it might include additional data such as the number of rows processed. The caller should not free the result directly. It will be freed when the associated <structname>PGresult</> handle is passed to @@ -2451,7 +2451,7 @@ size_t PQescapeString (char *to, const char *from, size_t length); <function>PQescapeStringConn</>; the difference is that it does not take <parameter>conn</> or <parameter>error</> parameters. Because of this, it cannot adjust its behavior depending on the connection properties (such as -character encoding) and therefore <emphasis>it may give the wrong results</>. +character encoding) and therefore <emphasis>it might give the wrong results</>. Also, it has no way to report error conditions. </para> <para> @@ -2552,7 +2552,7 @@ unsigned char *PQescapeBytea(const unsigned char *from, take a <structname>PGconn</> parameter. Because of this, it cannot adjust its behavior depending on the connection properties (in particular, whether standard-conforming strings are enabled) - and therefore <emphasis>it may give the wrong results</>. Also, it + and therefore <emphasis>it might give the wrong results</>. Also, it has no way to return an error message on failure. </para> @@ -2641,7 +2641,7 @@ applications. It has a couple of deficiencies, however, that can be of importan <itemizedlist> <listitem> <para> -<function>PQexec</function> waits for the command to be completed. The application may have other +<function>PQexec</function> waits for the command to be completed. The application might have other work to do (such as maintaining a user interface), in which case it won't want to block waiting for the response. </para> @@ -2698,7 +2698,7 @@ int PQsendQuery(PGconn *conn, const char *command); After successfully calling <function>PQsendQuery</function>, call <function>PQgetResult</function> one or more - times to obtain the results. <function>PQsendQuery</function> may not be called + times to obtain the results. <function>PQsendQuery</function> cannot be called again (on the same connection) until <function>PQgetResult</function> has returned a null pointer, indicating that the command is done. </para> @@ -2890,12 +2890,12 @@ but returns 0 if there was some kind of trouble (in which case <function>PQerrorMessage</function> can be consulted). Note that the result does not say whether any input data was actually collected. After calling -<function>PQconsumeInput</function>, the application may check +<function>PQconsumeInput</function>, the application can check <function>PQisBusy</function> and/or <function>PQnotifies</function> to see if their state has changed. </para> <para> -<function>PQconsumeInput</function> may be called even if the application is not +<function>PQconsumeInput</function> can be called even if the application is not prepared to deal with a result or notification just yet. The function will read available data and save it in a buffer, thereby causing a <function>select()</function> read-ready indication to go away. The @@ -2960,7 +2960,7 @@ server. This is relatively uncommon but can happen if very long SQL commands or data values are sent. (It is much more probable if the application sends data via <command>COPY IN</command>, however.) To prevent this possibility and achieve completely nonblocking database operation, the following additional -functions may be used. +functions can be used. <variablelist> <varlistentry> @@ -3168,7 +3168,7 @@ simple function calls to the server. <tip> <para> -This interface is somewhat obsolete, as one may achieve similar performance +This interface is somewhat obsolete, as one can achieve similar performance and greater functionality by setting up a prepared statement to define the function call. Then, executing the statement with binary transmission of parameters and results substitutes for a fast-path function call. @@ -3357,7 +3357,7 @@ if any notifications came in during the processing of the command. is returned to indicate success or failure of the transfer. Its status will be <literal>PGRES_COMMAND_OK</literal> for success or <literal>PGRES_FATAL_ERROR</literal> if some problem was encountered. - At this point further SQL commands may be issued via + At this point further SQL commands can be issued via <function>PQexec</function>. (It is not possible to execute other SQL commands using the same connection while the <command>COPY</command> operation is in progress.) @@ -3466,7 +3466,7 @@ value is -1. If the value is zero, wait for write-ready and try again.) </para> <para> -The application may divide the <command>COPY</command> data stream into buffer loads of any +The application can divide the <command>COPY</command> data stream into buffer loads of any convenient size. Buffer-load boundaries have no semantic significance when sending. The contents of the data stream must match the data format expected by the <command>COPY</> command; see @@ -3507,7 +3507,7 @@ value is -1. If the value is zero, wait for write-ready and try again.) <para> After successfully calling <function>PQputCopyEnd</>, call <function>PQgetResult</> to obtain the final result status of the -<command>COPY</> command. One may wait for +<command>COPY</> command. One can wait for this result to be available in the usual way. Then return to normal operation. </para> @@ -3575,7 +3575,7 @@ or the operation completes. <para> After <function>PQgetCopyData</> returns -1, call <function>PQgetResult</> to obtain the final result status of the -<command>COPY</> command. One may wait for +<command>COPY</> command. One can wait for this result to be available in the usual way. Then return to normal operation. </para> @@ -3818,7 +3818,7 @@ the connection's previous setting. In <firstterm>TERSE</> mode, returned messages include severity, primary text, and position only; this will normally fit on a single line. The default mode produces messages that include the above plus any detail, hint, or context -fields (these may span multiple lines). The <firstterm>VERBOSE</> +fields (these might span multiple lines). The <firstterm>VERBOSE</> mode includes all available fields. Changing the verbosity does not affect the messages available from already-existing <structname>PGresult</> objects, only subsequently-created ones. @@ -3888,7 +3888,7 @@ and so on. Instead, use this function to convert the password to encrypted form before it is sent. The arguments are the cleartext password, and the SQL name of the user it is for. The return value is a string allocated by <function>malloc</function>, or <symbol>NULL</symbol> if out of memory. -The caller may assume the string doesn't contain any special +The caller can assume the string doesn't contain any special characters that would require escaping. Use <function>PQfreemem</> to free the result when done with it. </para> @@ -4308,7 +4308,7 @@ This file should contain lines of the following format: <synopsis> <replaceable>hostname</replaceable>:<replaceable>port</replaceable>:<replaceable>database</replaceable>:<replaceable>username</replaceable>:<replaceable>password</replaceable> </synopsis> -Each of the first four fields may be a literal value, or <literal>*</literal>, +Each of the first four fields can be a literal value, or <literal>*</literal>, which matches anything. The password field from the first line that matches the current connection parameters will be used. (Therefore, put more-specific entries first when you are using wildcards.) diff --git a/doc/src/sgml/lobj.sgml b/doc/src/sgml/lobj.sgml index 47801bb733..604bf61fc2 100644 --- a/doc/src/sgml/lobj.sgml +++ b/doc/src/sgml/lobj.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/lobj.sgml,v 1.42 2006/10/23 18:10:31 petere Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/lobj.sgml,v 1.43 2007/01/31 20:56:17 momjian Exp $ --> <chapter id="largeObjects"> <title id="largeObjects-title">Large Objects</title> @@ -20,7 +20,7 @@ large object data. We use the <application>libpq</application> C library for the examples in this chapter, but most programming interfaces native to <productname>PostgreSQL</productname> support - equivalent functionality. Other interfaces may use the large + equivalent functionality. Other interfaces might use the large object interface internally to provide generic support for large values. This is not described here. </para> @@ -305,7 +305,7 @@ int lo_tell(PGconn *conn, int fd); <title>Closing a Large Object Descriptor</title> <para> - A large object descriptor may be closed by calling + A large object descriptor can be closed by calling <synopsis> int lo_close(PGconn *conn, int fd); </synopsis> @@ -392,7 +392,7 @@ SELECT lo_export(image.raster, '/tmp/motd') FROM image <para> <xref linkend="lo-example"> is a sample program which shows how the large object interface - in <application>libpq</> can be used. Parts of the program are + in <application>libpq</> can be used. Parts of the program are commented out but are left in the source for the reader's benefit. This program can also be found in <filename>src/test/examples/testlo.c</filename> in the source distribution. diff --git a/doc/src/sgml/maintenance.sgml b/doc/src/sgml/maintenance.sgml index 4b5b2c5cc3..1da03fcbf1 100644 --- a/doc/src/sgml/maintenance.sgml +++ b/doc/src/sgml/maintenance.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/maintenance.sgml,v 1.67 2007/01/31 04:13:22 momjian Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/maintenance.sgml,v 1.68 2007/01/31 20:56:17 momjian Exp $ --> <chapter id="maintenance"> <title>Routine Database Maintenance Tasks</title> @@ -131,7 +131,7 @@ <para> Clearly, a table that receives frequent updates or deletes will need to be vacuumed more often than tables that are seldom updated. It - may be useful to set up periodic <application>cron</> tasks that + might be useful to set up periodic <application>cron</> tasks that <command>VACUUM</command> only selected tables, skipping tables that are known not to change often. This is only likely to be helpful if you have both large heavily-updated tables and large seldom-updated tables — the @@ -185,7 +185,7 @@ If you have multiple databases in a cluster, don't forget to <command>VACUUM</command> each one; the program <xref linkend="app-vacuumdb" endterm="app-vacuumdb-title"> - may be helpful. + might be helpful. </para> <para> @@ -226,14 +226,14 @@ generate good plans for queries. These statistics are gathered by the <command>ANALYZE</> command, which can be invoked by itself or as an optional step in <command>VACUUM</>. It is important to have - reasonably accurate statistics, otherwise poor choices of plans may + reasonably accurate statistics, otherwise poor choices of plans might degrade database performance. </para> <para> As with vacuuming for space recovery, frequent updates of statistics are more useful for heavily-updated tables than for seldom-updated - ones. But even for a heavily-updated table, there may be no need for + ones. But even for a heavily-updated table, there might be no need for statistics updates if the statistical distribution of the data is not changing much. A simple rule of thumb is to think about how much the minimum and maximum values of the columns in the table change. @@ -241,7 +241,7 @@ of row update will have a constantly-increasing maximum value as rows are added and updated; such a column will probably need more frequent statistics updates than, say, a column containing URLs for - pages accessed on a website. The URL column may receive changes just + pages accessed on a website. The URL column might receive changes just as often, but the statistical distribution of its values probably changes relatively slowly. </para> @@ -257,11 +257,11 @@ <tip> <para> - Although per-column tweaking of <command>ANALYZE</> frequency may not be - very productive, you may well find it worthwhile to do per-column + Although per-column tweaking of <command>ANALYZE</> frequency might not be + very productive, you might well find it worthwhile to do per-column adjustment of the level of detail of the statistics collected by <command>ANALYZE</>. Columns that are heavily used in <literal>WHERE</> clauses - and have highly irregular data distributions may require a finer-grain + and have highly irregular data distributions might require a finer-grain data histogram than other columns. See <command>ALTER TABLE SET STATISTICS</>. </para> @@ -271,7 +271,7 @@ Recommended practice for most sites is to schedule a database-wide <command>ANALYZE</> once a day at a low-usage time of day; this can usefully be combined with a nightly <command>VACUUM</>. However, - sites with relatively slowly changing table statistics may find that + sites with relatively slowly changing table statistics might find that this is overkill, and that less-frequent <command>ANALYZE</> runs are sufficient. </para> @@ -381,7 +381,7 @@ <para> One disadvantage of decreasing <varname>vacuum_freeze_min_age</> is that - it may cause <command>VACUUM</> to do useless work: changing a table row's + it might cause <command>VACUUM</> to do useless work: changing a table row's XID to <literal>FrozenXID</> is a waste of time if the row is modified soon thereafter (causing it to acquire a new XID). So the setting should be large enough that rows are not frozen until they are unlikely to change @@ -510,7 +510,7 @@ vacuum threshold = vacuum base threshold + vacuum scale factor * number of tuple The number of obsolete tuples is obtained from the statistics collector; it is a semi-accurate count updated by each <command>UPDATE</command> and <command>DELETE</command> operation. (It - is only semi-accurate because some information may be lost under heavy + is only semi-accurate because some information might be lost under heavy load.) For analyze, a similar condition is used: the threshold, defined as <programlisting> analyze threshold = analyze base threshold + analyze scale factor * number of tuples @@ -658,7 +658,7 @@ analyze threshold = analyze base threshold + analyze scale factor * number of tu <command>postgres</command> into a file, you will have log output, but the only way to truncate the log file is to stop and restart - the server. This may be OK if you are using + the server. This might be OK if you are using <productname>PostgreSQL</productname> in a development environment, but few production servers would find this behavior acceptable. </para> @@ -707,7 +707,7 @@ pg_ctl start | rotatelogs /var/log/pgsql_log 86400 <para> On many systems, however, <application>syslog</> is not very reliable, - particularly with large log messages; it may truncate or drop messages + particularly with large log messages; it might truncate or drop messages just when you need them the most. Also, on <productname>Linux</>, <application>syslog</> will sync each message to disk, yielding poor performance. (You can use a <literal>-</> at the start of the file name diff --git a/doc/src/sgml/manage-ag.sgml b/doc/src/sgml/manage-ag.sgml index 370537c8c0..984598211a 100644 --- a/doc/src/sgml/manage-ag.sgml +++ b/doc/src/sgml/manage-ag.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/manage-ag.sgml,v 2.51 2007/01/22 02:47:56 momjian Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/manage-ag.sgml,v 2.52 2007/01/31 20:56:17 momjian Exp $ --> <chapter id="managing-databases"> <title>Managing Databases</title> @@ -143,7 +143,7 @@ createdb <replaceable class="parameter">dbname</replaceable> exactly as described above. The <xref linkend="app-createdb"> reference page contains the invocation details. Note that <command>createdb</> without any arguments will create - a database with the current user name, which may or may not be what + a database with the current user name, which might or might not be what you want. </para> @@ -204,7 +204,7 @@ createdb -O <replaceable>rolename</> <replaceable>dbname</> <literal>pg_dump</> dump: the dump script should be restored in a virgin database to ensure that one recreates the correct contents of the dumped database, without any conflicts with additions that - may now be present in <literal>template1</>. + can now be present in <literal>template1</>. </para> <para> @@ -221,7 +221,7 @@ createdb -T template0 <replaceable>dbname</> <para> It is possible to create additional template databases, and indeed - one may copy any database in a cluster by specifying its name + one can copy any database in a cluster by specifying its name as the template for <command>CREATE DATABASE</>. It is important to understand, however, that this is not (yet) intended as a general-purpose <quote><command>COPY DATABASE</command></quote> facility. @@ -236,11 +236,11 @@ createdb -T template0 <replaceable>dbname</> Two useful flags exist in <literal>pg_database</literal><indexterm><primary>pg_database</></> for each database: the columns <literal>datistemplate</literal> and <literal>datallowconn</literal>. <literal>datistemplate</literal> - may be set to indicate that a database is intended as a template for - <command>CREATE DATABASE</>. If this flag is set, the database may be + can be set to indicate that a database is intended as a template for + <command>CREATE DATABASE</>. If this flag is set, the database can be cloned by any user with <literal>CREATEDB</> privileges; if it is not set, only superusers - and the owner of the database may clone it. + and the owner of the database can clone it. If <literal>datallowconn</literal> is false, then no new connections to that database will be allowed (but existing sessions are not killed simply by setting the flag false). The <literal>template0</literal> @@ -265,7 +265,7 @@ createdb -T template0 <replaceable>dbname</> The <literal>postgres</> database is also created when a database cluster is initialized. This database is meant as a default database for users and applications to connect to. It is simply a copy of - <literal>template1</> and may be dropped and recreated if required. + <literal>template1</> and can be dropped and recreated if required. </para> </note> </sect1> diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index d7813d5638..fe6c94c077 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/monitoring.sgml,v 1.43 2006/12/08 19:16:17 tgl Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/monitoring.sgml,v 1.44 2007/01/31 20:56:18 momjian Exp $ --> <chapter id="monitoring"> <title>Monitoring Database Activity</title> @@ -26,7 +26,7 @@ but one should not neglect regular Unix monitoring programs such as <command>ps</>, <command>top</>, <command>iostat</>, and <command>vmstat</>. Also, once one has identified a - poorly-performing query, further investigation may be needed using + poorly-performing query, further investigation might be needed using <productname>PostgreSQL</productname>'s <xref linkend="sql-explain" endterm="sql-explain-title"> command. <xref linkend="using-explain"> discusses <command>EXPLAIN</> @@ -75,7 +75,7 @@ postgres: <replaceable>user</> <replaceable>database</> <replaceable>host</> <re The user, database, and connection source host items remain the same for the life of the client connection, but the activity indicator changes. - The activity may be <literal>idle</> (i.e., waiting for a client command), + The activity can be <literal>idle</> (i.e., waiting for a client command), <literal>idle in transaction</> (waiting for client inside a <command>BEGIN</> block), or a command type name such as <literal>SELECT</>. Also, <literal>waiting</> is attached if the server process is presently waiting @@ -141,7 +141,7 @@ postgres: <replaceable>user</> <replaceable>database</> <replaceable>host</> <re <para> The parameter <xref linkend="guc-stats-start-collector"> must be set to <literal>true</> for the statistics collector to be launched - at all. This is the default and recommended setting, but it may be + at all. This is the default and recommended setting, but it can be turned off if you have no interest in statistics and want to squeeze out every last drop of overhead. (The savings is likely to be small, however.) Note that this option cannot be changed while @@ -423,8 +423,8 @@ postgres: <replaceable>user</> <replaceable>database</> <replaceable>host</> <re invoking a kernel call. However, these statistics do not give the entire story: due to the way in which <productname>PostgreSQL</> handles disk I/O, data that is not in the - <productname>PostgreSQL</> buffer cache may still reside in the - kernel's I/O cache, and may therefore still be fetched without + <productname>PostgreSQL</> buffer cache might still reside in the + kernel's I/O cache, and might therefore still be fetched without requiring a physical read. Users interested in obtaining more detailed information on <productname>PostgreSQL</> I/O behavior are advised to use the <productname>PostgreSQL</> statistics collector @@ -971,7 +971,7 @@ Total time (ns) 2312105013 </para> <para> You should remember that trace programs need to be carefully written and - debugged prior to their use, otherwise the trace information collected may + debugged prior to their use, otherwise the trace information collected might be meaningless. In most cases where problems are found it is the instrumentation that is at fault, not the underlying system. When discussing information found using dynamic tracing, be sure to enclose @@ -1027,7 +1027,7 @@ StartTransaction(void) </para> <para> - The dynamic tracing utility may require you to further define these trace + The dynamic tracing utility might require you to further define these trace points. For example, DTrace requires you to add new probes to the file <filename>src/backend/utils/probes.d</> as shown here: <programlisting> diff --git a/doc/src/sgml/mvcc.sgml b/doc/src/sgml/mvcc.sgml index 8f6984a7e9..02161a3a4c 100644 --- a/doc/src/sgml/mvcc.sgml +++ b/doc/src/sgml/mvcc.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/mvcc.sgml,v 2.65 2006/12/01 01:04:36 tgl Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/mvcc.sgml,v 2.66 2007/01/31 20:56:18 momjian Exp $ --> <chapter id="mvcc"> <title>Concurrency Control</title> @@ -215,7 +215,7 @@ Committed and Serializable. When you select the level Read Uncommitted you really get Read Committed, and when you select Repeatable Read you really get Serializable, so the actual - isolation level may be stricter than what you select. This is + isolation level might be stricter than what you select. This is permitted by the SQL standard: the four isolation levels only define which phenomena must not happen, they do not define which phenomena must happen. The reason that <productname>PostgreSQL</> @@ -261,7 +261,7 @@ behave the same as <command>SELECT</command> in terms of searching for target rows: they will only find target rows that were committed as of the command start time. However, such a target - row may have already been updated (or deleted or locked) by + row might have already been updated (or deleted or locked) by another concurrent transaction by the time it is found. In this case, the would-be updater will wait for the first updating transaction to commit or roll back (if it is still in progress). If the first updater rolls back, @@ -314,7 +314,7 @@ COMMIT; <para> The partial transaction isolation provided by Read Committed mode is adequate for many applications, and this mode is fast and simple to use. - However, for applications that do complex queries and updates, it may + However, for applications that do complex queries and updates, it might be necessary to guarantee a more rigorously consistent view of the database than the Read Committed mode provides. </para> @@ -359,7 +359,7 @@ COMMIT; in terms of searching for target rows: they will only find target rows that were committed as of the transaction start time. However, such a target - row may have already been updated (or deleted or locked) by + row might have already been updated (or deleted or locked) by another concurrent transaction by the time it is found. In this case, the serializable transaction will wait for the first updating transaction to commit or roll back (if it is still in progress). If the first updater rolls back, @@ -386,7 +386,7 @@ ERROR: could not serialize access due to concurrent update </para> <para> - Note that only updating transactions may need to be retried; read-only + Note that only updating transactions might need to be retried; read-only transactions will never have serialization conflicts. </para> @@ -395,9 +395,9 @@ ERROR: could not serialize access due to concurrent update transaction sees a wholly consistent view of the database. However, the application has to be prepared to retry transactions when concurrent updates make it impossible to sustain the illusion of serial execution. - Since the cost of redoing complex transactions may be significant, + Since the cost of redoing complex transactions might be significant, this mode is recommended only when updating transactions contain logic - sufficiently complex that they may give wrong answers in Read + sufficiently complex that they might give wrong answers in Read Committed mode. Most commonly, Serializable mode is necessary when a transaction executes several successive commands that must see identical views of the database. @@ -418,7 +418,7 @@ ERROR: could not serialize access due to concurrent update The intuitive meaning (and mathematical definition) of <quote>serializable</> execution is that any two successfully committed concurrent transactions will appear to have executed strictly serially, - one after the other — although which one appeared to occur first may + one after the other — although which one appeared to occur first might not be predictable in advance. It is important to realize that forbidding the undesirable behaviors listed in <xref linkend="mvcc-isolevel-table"> is not sufficient to guarantee true serializability, and in fact @@ -538,10 +538,10 @@ SELECT SUM(value) FROM mytab WHERE class = 2; between one lock mode and another is the set of lock modes with which each conflicts. Two transactions cannot hold locks of conflicting modes on the same table at the same time. (However, a transaction - never conflicts with itself. For example, it may acquire + never conflicts with itself. For example, it might acquire <literal>ACCESS EXCLUSIVE</literal> lock and later acquire <literal>ACCESS SHARE</literal> lock on the same table.) Non-conflicting - lock modes may be held concurrently by many transactions. Notice in + lock modes can be held concurrently by many transactions. Notice in particular that some lock modes are self-conflicting (for example, an <literal>ACCESS EXCLUSIVE</literal> lock cannot be held by more than one transaction at a time) while others are not self-conflicting (for example, @@ -760,7 +760,7 @@ SELECT SUM(value) FROM mytab WHERE class = 2; To acquire an exclusive row-level lock on a row without actually modifying the row, select the row with <command>SELECT FOR UPDATE</command>. Note that once the row-level lock is acquired, - the transaction may update the row multiple times without + the transaction can update the row multiple times without fear of conflicts. </para> @@ -777,7 +777,7 @@ SELECT SUM(value) FROM mytab WHERE class = 2; <productname>PostgreSQL</productname> doesn't remember any information about modified rows in memory, so it has no limit to the number of rows locked at one time. However, locking a row - may cause a disk write; thus, for example, <command>SELECT FOR + might cause a disk write; thus, for example, <command>SELECT FOR UPDATE</command> will modify selected rows to mark them locked, and so will result in disk writes. </para> @@ -863,7 +863,7 @@ UPDATE accounts SET balance = balance - 100.00 WHERE acctnum = 22222; occurred. One should also ensure that the first lock acquired on an object in a transaction is the highest mode that will be needed for that object. If it is not feasible to verify this in - advance, then deadlocks may be handled on-the-fly by retrying + advance, then deadlocks can be handled on-the-fly by retrying transactions that are aborted due to deadlock. </para> @@ -977,12 +977,12 @@ SELECT pg_advisory_lock(q.id) FROM <para> Another way to think about it is that each transaction sees a snapshot of the database contents, and concurrently - executing transactions may very well see different snapshots. So the + executing transactions might very well see different snapshots. So the whole concept of <quote>now</quote> is somewhat ill-defined anyway. This is not normally a big problem if the client applications are isolated from each other, but if the clients can communicate via channels outside the database - then serious confusion may ensue. + then serious confusion might ensue. </para> <para> @@ -1026,7 +1026,7 @@ SELECT pg_advisory_lock(q.id) FROM lock(s) before performing queries. A lock obtained by a serializable transaction guarantees that no other transactions modifying the table are still running, but if the snapshot seen by the - transaction predates obtaining the lock, it may predate some now-committed + transaction predates obtaining the lock, it might predate some now-committed changes in the table. A serializable transaction's snapshot is actually frozen at the start of its first query or data-modification command (<literal>SELECT</>, <literal>INSERT</>, @@ -1092,7 +1092,7 @@ SELECT pg_advisory_lock(q.id) FROM read/write access. Locks are released immediately after each index row is fetched or inserted. But note that a GIN-indexed value insertion usually produces several index key insertions - per row, so GIN may do substantial work for a single value's + per row, so GIN might do substantial work for a single value's insertion. </para> </listitem> diff --git a/doc/src/sgml/nls.sgml b/doc/src/sgml/nls.sgml index 6dec267263..b2161eb987 100644 --- a/doc/src/sgml/nls.sgml +++ b/doc/src/sgml/nls.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/nls.sgml,v 1.14 2006/03/10 19:10:48 momjian Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/nls.sgml,v 1.15 2007/01/31 20:56:18 momjian Exp $ --> <chapter id="nls"> <chapterinfo> @@ -108,7 +108,7 @@ msgstr "another translated" <para> The # character introduces a comment. If whitespace immediately follows the # character, then this is a comment maintained by the - translator. There may also be automatic comments, which have a + translator. There can also be automatic comments, which have a non-whitespace character immediately following the #. These are maintained by the various tools that operate on the PO files and are intended to aid the translator. @@ -157,7 +157,7 @@ msgstr "another translated" ISO 639-1 two-letter language code (in lower case)</ulink>, e.g., <filename>fr.po</filename> for French. If there is really a need for more than one translation effort per language then the files - may also be named + can also be named <filename><replaceable>language</replaceable>_<replaceable>region</replaceable>.po</filename> where <replaceable>region</replaceable> is the <ulink url="http://www.din.de/gremien/nas/nabd/iso3166ma/codlstp1/en_listp1.html"> @@ -187,11 +187,11 @@ gmake init-po <programlisting> AVAIL_LANGUAGES := de fr </programlisting> - (Other languages may appear, of course.) + (Other languages can appear, of course.) </para> <para> - As the underlying program or library changes, messages may be + As the underlying program or library changes, messages might be changed or added by the programmers. In this case you do not need to start from scratch. Instead, run the command <programlisting> @@ -212,7 +212,7 @@ gmake update-po <para> The PO files can be edited with a regular text editor. The translator should only change the area between the quotes after - the msgstr directive, may add comments and alter the fuzzy flag. + the msgstr directive, add comments, and alter the fuzzy flag. There is (unsurprisingly) a PO mode for Emacs, which I find quite useful. </para> @@ -255,7 +255,7 @@ msgstr "Die Datei %2$s hat %1$u Zeichen." <literal><replaceable>digits</replaceable>$</literal> needs to follow the % immediately, before any other format manipulators. (This feature really exists in the <function>printf</function> - family of functions. You may not have heard of it before because + family of functions. You might not have heard of it before because there is little use for it outside of message internationalization.) </para> @@ -268,7 +268,7 @@ msgstr "Die Datei %2$s hat %1$u Zeichen." normally. The corrected string can be merged in when the program sources have been updated. If the original string contains a factual mistake, report that (or fix it yourself) - and do not translate it. Instead, you may mark the string with + and do not translate it. Instead, you can mark the string with a comment in the PO file. </para> </listitem> @@ -280,7 +280,7 @@ msgstr "Die Datei %2$s hat %1$u Zeichen." open file %s</literal>) should probably not start with a capital letter (if your language distinguishes letter case) or end with a period (if your language uses punctuation marks). - It may help to read <xref linkend="error-style-guide">. + It might help to read <xref linkend="error-style-guide">. </para> </listitem> @@ -353,7 +353,7 @@ fprintf(stderr, gettext("panic level %d\n"), lvl); </para> <para> - This may tend to add a lot of clutter. One common shortcut is to use + This tends to add a lot of clutter. One common shortcut is to use <programlisting> #define _(x) gettext(x) </programlisting> @@ -451,9 +451,9 @@ fprintf(stderr, gettext("panic level %d\n"), lvl); <programlisting> printf("Files were %s.\n", flag ? "copied" : "removed"); </programlisting> - The word order within the sentence may be different in other + The word order within the sentence might be different in other languages. Also, even if you remember to call gettext() on each - fragment, the fragments may not translate well separately. It's + fragment, the fragments might not translate well separately. It's better to duplicate a little code so that each message to be translated is a coherent whole. Only numbers, file names, and such-like run-time variables should be inserted at run time into @@ -476,7 +476,7 @@ else printf("copied %d files", n): </programlisting> then be disappointed. Some languages have more than two forms, - with some peculiar rules. We may have a solution for this in + with some peculiar rules. We might have a solution for this in the future, but for now the matter is best avoided altogether. You could write: <programlisting> diff --git a/doc/src/sgml/perform.sgml b/doc/src/sgml/perform.sgml index e47edcd331..37db91ccbc 100644 --- a/doc/src/sgml/perform.sgml +++ b/doc/src/sgml/perform.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/perform.sgml,v 1.60 2007/01/25 02:17:25 momjian Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/perform.sgml,v 1.61 2007/01/31 20:56:18 momjian Exp $ --> <chapter id="performance-tips"> <title>Performance Tips</title> @@ -90,7 +90,7 @@ EXPLAIN SELECT * FROM tenk1; <listitem> <para> - Estimated total cost (If all rows were to be retrieved, which they may + Estimated total cost (If all rows were to be retrieved, though they might not be: for example, a query with a <literal>LIMIT</> clause will stop short of paying the total cost of the <literal>Limit</> plan node's input node.) @@ -230,7 +230,7 @@ EXPLAIN SELECT * FROM tenk1 WHERE unique1 < 100; </para> <para> - If the <literal>WHERE</> condition is selective enough, the planner may + If the <literal>WHERE</> condition is selective enough, the planner might switch to a <quote>simple</> index scan plan: <programlisting> @@ -426,7 +426,7 @@ EXPLAIN ANALYZE SELECT * FROM tenk1 t1, tenk2 t2 WHERE t1.unique1 < 100 AND t run time will normally be just a little larger than the total time reported for the top-level plan node. For <command>INSERT</>, <command>UPDATE</>, and <command>DELETE</> commands, the total run time - may be considerably larger, because it includes the time spent processing + might be considerably larger, because it includes the time spent processing the result rows. In these commands, the time for the top plan node essentially is the time spent computing the new rows and/or locating the old ones, but it doesn't include the time spent applying the changes. @@ -438,7 +438,7 @@ EXPLAIN ANALYZE SELECT * FROM tenk1 t1, tenk2 t2 WHERE t1.unique1 < 100 AND t It is worth noting that <command>EXPLAIN</> results should not be extrapolated to situations other than the one you are actually testing; for example, results on a toy-sized table can't be assumed to apply to large tables. - The planner's cost estimates are not linear and so it may well choose + The planner's cost estimates are not linear and so it might choose a different plan for a larger or smaller table. An extreme example is that on a table that only occupies one disk page, you'll nearly always get a sequential scan plan whether indexes are available or not. @@ -564,10 +564,10 @@ SELECT attname, n_distinct, most_common_vals FROM pg_stats WHERE tablename = 'ro command, or globally by setting the <xref linkend="guc-default-statistics-target"> configuration variable. The default limit is presently 10 entries. Raising the limit - may allow more accurate planner estimates to be made, particularly for + might allow more accurate planner estimates to be made, particularly for columns with irregular data distributions, at the price of consuming more space in <structname>pg_statistic</structname> and slightly more - time to compute the estimates. Conversely, a lower limit may be + time to compute the estimates. Conversely, a lower limit might be appropriate for columns with simple data distributions. </para> @@ -605,7 +605,7 @@ SELECT * FROM a, b, c WHERE a.id = b.id AND b.ref = c.id; between two input tables, so it's necessary to build up the result in one or another of these fashions.) The important point is that these different join possibilities give semantically equivalent - results but may have hugely different execution costs. Therefore, + results but might have hugely different execution costs. Therefore, the planner will explore all of them to try to find the most efficient query plan. </para> @@ -615,7 +615,7 @@ SELECT * FROM a, b, c WHERE a.id = b.id AND b.ref = c.id; orders to worry about. But the number of possible join orders grows exponentially as the number of tables expands. Beyond ten or so input tables it's no longer practical to do an exhaustive search of all the - possibilities, and even for six or seven tables planning may take an + possibilities, and even for six or seven tables planning might take an annoyingly long time. When there are too many input tables, the <productname>PostgreSQL</productname> planner will switch from exhaustive search to a <firstterm>genetic</firstterm> probabilistic search @@ -638,7 +638,7 @@ SELECT * FROM a LEFT JOIN (b JOIN c ON (b.ref = c.id)) ON (a.id = b.id); Therefore the planner has no choice of join order here: it must join B to C and then join A to that result. Accordingly, this query takes less time to plan than the previous query. In other cases, the planner - may be able to determine that more than one join order is safe. + might be able to determine that more than one join order is safe. For example, given <programlisting> SELECT * FROM a LEFT JOIN b ON (a.bid = b.id) LEFT JOIN c ON (a.cid = c.id); @@ -751,7 +751,7 @@ SELECT * FROM x, y, a, b, c WHERE something AND somethingelse; <title>Populating a Database</title> <para> - One may need to insert a large amount of data when first populating + One might need to insert a large amount of data when first populating a database. This section contains some suggestions on how to make this process as efficient as possible. </para> @@ -767,7 +767,7 @@ SELECT * FROM x, y, a, b, c WHERE something AND somethingelse; <para> Turn off autocommit and just do one commit at the end. (In plain SQL, this means issuing <command>BEGIN</command> at the start and - <command>COMMIT</command> at the end. Some client libraries may + <command>COMMIT</command> at the end. Some client libraries might do this behind your back, in which case you need to make sure the library does it when you want it done.) If you allow each insertion to be committed separately, @@ -795,7 +795,7 @@ SELECT * FROM x, y, a, b, c WHERE something AND somethingelse; </para> <para> - If you cannot use <command>COPY</command>, it may help to use <xref + If you cannot use <command>COPY</command>, it might help to use <xref linkend="sql-prepare" endterm="sql-prepare-title"> to create a prepared <command>INSERT</command> statement, and then use <command>EXECUTE</command> as many times as required. This avoids @@ -840,9 +840,9 @@ SELECT * FROM x, y, a, b, c WHERE something AND somethingelse; <para> If you are adding large amounts of data to an existing table, - it may be a win to drop the index, + it might be a win to drop the index, load the table, and then recreate the index. Of course, the - database performance for other users may be adversely affected + database performance for other users might be adversely affected during the time that the index is missing. One should also think twice before dropping unique indexes, since the error checking afforded by the unique constraint will be lost while the index is @@ -855,7 +855,7 @@ SELECT * FROM x, y, a, b, c WHERE something AND somethingelse; <para> Just as with indexes, a foreign key constraint can be checked - <quote>in bulk</> more efficiently than row-by-row. So it may be + <quote>in bulk</> more efficiently than row-by-row. So it might be useful to drop foreign key constraints, load data, and re-create the constraints. Again, there is a trade-off between data load speed and loss of error checking while the constraint is missing. @@ -897,8 +897,8 @@ SELECT * FROM x, y, a, b, c WHERE something AND somethingelse; <title>Turn off <varname>archive_command</varname></title> <para> - When loading large amounts of data you may want to unset the - <xref linkend="guc-archive-command"> before loading. It may be + When loading large amounts of data you might want to unset the + <xref linkend="guc-archive-command"> before loading. It might be faster to take a new base backup once the load has completed than to allow a large archive to accumulate. </para> @@ -926,7 +926,7 @@ SELECT * FROM x, y, a, b, c WHERE something AND somethingelse; includes bulk loading large amounts of data into the table. Running <command>ANALYZE</command> (or <command>VACUUM ANALYZE</command>) ensures that the planner has up-to-date statistics about the - table. With no statistics or obsolete statistics, the planner may + table. With no statistics or obsolete statistics, the planner might make poor decisions during query planning, leading to poor performance on any tables with inaccurate or nonexistent statistics. diff --git a/doc/src/sgml/planstats.sgml b/doc/src/sgml/planstats.sgml index 4d07bd4da5..17a06b7cff 100644 --- a/doc/src/sgml/planstats.sgml +++ b/doc/src/sgml/planstats.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/planstats.sgml,v 1.7 2006/09/16 00:30:14 momjian Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/planstats.sgml,v 1.8 2007/01/31 20:56:18 momjian Exp $ --> <chapter id="planner-stats-details"> <title>How the Planner Uses Statistics</title> @@ -21,7 +21,7 @@ <para> The outputs and algorithms shown below are taken from version 8.0. - The behavior of earlier (or later) versions may vary. + The behavior of earlier (or later) versions might vary. </para> <sect1 id="row-estimation-examples"> @@ -56,7 +56,7 @@ SELECT reltuples, relpages FROM pg_class WHERE relname = 'tenk1'; 345 | 10000 </programlisting> The planner will check the <structfield>relpages</structfield> - estimate (this is a cheap operation) and if incorrect may scale + estimate (this is a cheap operation) and if incorrect might scale <structfield>reltuples</structfield> to obtain a row estimate. In this case it does not, thus: diff --git a/doc/src/sgml/plperl.sgml b/doc/src/sgml/plperl.sgml index ce95e1ed08..9dddf6598a 100644 --- a/doc/src/sgml/plperl.sgml +++ b/doc/src/sgml/plperl.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/plperl.sgml,v 2.60 2007/01/30 22:29:23 momjian Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/plperl.sgml,v 2.61 2007/01/31 20:56:18 momjian Exp $ --> <chapter id="plperl"> <title>PL/Perl - Perl Procedural Language</title> @@ -20,7 +20,7 @@ <para> The usual advantage to using PL/Perl is that this allows use, within stored functions, of the manyfold <quote>string munging</quote> operators and functions available for Perl. Parsing - complex strings may be be easier using Perl than it is with the + complex strings might be be easier using Perl than it is with the string functions and control structures provided in PL/pgSQL.</para> <para> @@ -382,7 +382,7 @@ SELECT * FROM test_munge(); </para> <para> <literal>spi_query</literal> and <literal>spi_fetchrow</literal> - work together as a pair for row sets which may be large, or for cases + work together as a pair for row sets which might be large, or for cases where you wish to return rows as they arrive. <literal>spi_fetchrow</literal> works <emphasis>only</emphasis> with <literal>spi_query</literal>. The following example illustrates how @@ -429,7 +429,7 @@ SELECT * from lotsa_md5(500); <para> The advantage of prepared queries is that is it possible to use one prepared plan for more - than one query execution. After the plan is not needed anymore, it may be freed with + than one query execution. After the plan is not needed anymore, it can be freed with <literal>spi_freeplan</literal>: </para> @@ -601,7 +601,7 @@ $$ LANGUAGE plperl; external modules). There is no way to access internals of the database server process or to gain OS-level access with the permissions of the server process, - as a C function can do. Thus, any unprivileged database user may + as a C function can do. Thus, any unprivileged database user can be permitted to use this language. </para> diff --git a/doc/src/sgml/plpgsql.sgml b/doc/src/sgml/plpgsql.sgml index 7eea925512..d5a015ef03 100644 --- a/doc/src/sgml/plpgsql.sgml +++ b/doc/src/sgml/plpgsql.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/plpgsql.sgml,v 1.103 2007/01/30 22:29:23 momjian Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/plpgsql.sgml,v 1.104 2007/01/31 20:56:18 momjian Exp $ --> <chapter id="plpgsql"> <title><application>PL/pgSQL</application> - <acronym>SQL</acronym> Procedural Language</title> @@ -84,7 +84,7 @@ substantially reduce the total amount of time required to parse and generate execution plans for the statements in a <application>PL/pgSQL</> function. A disadvantage is that errors - in a specific expression or command may not be detected until that + in a specific expression or command cannot be detected until that part of the function is reached in execution. </para> @@ -208,7 +208,7 @@ $$ LANGUAGE plpgsql; </para> <para> - <application>PL/pgSQL</> functions may also be declared to accept + <application>PL/pgSQL</> functions can also be declared to accept and return the polymorphic types <type>anyelement</type> and <type>anyarray</type>. The actual data types handled by a polymorphic function can vary from call to @@ -224,7 +224,7 @@ $$ LANGUAGE plpgsql; </para> <para> - Finally, a <application>PL/pgSQL</> function may be declared to return + Finally, a <application>PL/pgSQL</> function can be declared to return <type>void</> if it has no useful return value. </para> @@ -313,7 +313,7 @@ $PROC$ LANGUAGE plpgsql; <para> The following chart shows what you have to do when writing quote - marks without dollar quoting. It may be useful when translating + marks without dollar quoting. It might be useful when translating pre-dollar quoting code into something more comprehensible. </para> @@ -766,13 +766,13 @@ user_id users.user_id%TYPE; type of the structure you are referencing, and most importantly, if the data type of the referenced item changes in the future (for instance: you change the type of <literal>user_id</> - from <type>integer</type> to <type>real</type>), you may not need + from <type>integer</type> to <type>real</type>), you might not need to change your function definition. </para> <para> <literal>%TYPE</literal> is particularly valuable in polymorphic - functions, since the data types needed for internal variables may + functions, since the data types needed for internal variables can change from one call to the next. Appropriate variables can be created by applying <literal>%TYPE</literal> to the function's arguments or result placeholders. @@ -866,7 +866,7 @@ SELECT merge_fields(t.*) FROM table1 t WHERE ... ; Note that <literal>RECORD</> is not a true data type, only a placeholder. One should also realize that when a <application>PL/pgSQL</application> function is declared to return type <type>record</>, this is not quite the - same concept as a record variable, even though such a function may well + same concept as a record variable, even though such a function might use a record variable to hold its result. In both cases the actual row structure is unknown when the function is written, but for a function returning <type>record</> the actual structure is determined when the @@ -1530,7 +1530,7 @@ GET DIAGNOSTICS integer_var = ROW_COUNT; loops). <literal>FOUND</literal> is set this way when the <command>FOR</> loop exits; inside the execution of the loop, <literal>FOUND</literal> is not modified by the - <command>FOR</> statement, although it may be changed by the + <command>FOR</> statement, although it might be changed by the execution of other statements within the loop body. </para> </listitem> @@ -1671,10 +1671,10 @@ SELECT * FROM some_func(); for <application>PL/pgSQL</> stores the entire result set before returning from the function, as discussed above. That means that if a <application>PL/pgSQL</> function produces a - very large result set, performance may be poor: data will be + very large result set, performance might be poor: data will be written to disk to avoid memory exhaustion, but the function itself will not return until the entire result set has been - generated. A future version of <application>PL/pgSQL</> may + generated. A future version of <application>PL/pgSQL</> might allow users to define set-returning functions that do not have this limitation. Currently, the point at which data begins being written to disk is controlled by the @@ -2364,7 +2364,7 @@ SELECT merge_db(1, 'dennis'); <synopsis> <replaceable>name</replaceable> CURSOR <optional> ( <replaceable>arguments</replaceable> ) </optional> FOR <replaceable>query</replaceable>; </synopsis> - (<literal>FOR</> may be replaced by <literal>IS</> for + (<literal>FOR</> can be replaced by <literal>IS</> for <productname>Oracle</productname> compatibility.) <replaceable>arguments</replaceable>, if specified, is a comma-separated list of pairs <literal><replaceable>name</replaceable> @@ -2382,7 +2382,7 @@ DECLARE curs3 CURSOR (key integer) IS SELECT * FROM tenk1 WHERE unique1 = key; </programlisting> All three of these variables have the data type <type>refcursor</>, - but the first may be used with any query, while the second has + but the first can be used with any query, while the second has a fully specified query already <firstterm>bound</> to it, and the last has a parameterized query bound to it. (<literal>key</> will be replaced by an integer parameter value when the cursor is opened.) @@ -2516,10 +2516,10 @@ FETCH <replaceable>cursor</replaceable> INTO <replaceable>target</replaceable>; <para> <command>FETCH</command> retrieves the next row from the - cursor into a target, which may be a row variable, a record + cursor into a target, which might be a row variable, a record variable, or a comma-separated list of simple variables, just like <command>SELECT INTO</command>. As with <command>SELECT - INTO</command>, the special variable <literal>FOUND</literal> may + INTO</command>, the special variable <literal>FOUND</literal> can be checked to see whether a row was obtained or not. </para> @@ -2902,7 +2902,7 @@ RAISE EXCEPTION 'Nonexistent ID --> %', user_id; </para> <para> - Row-level triggers fired <literal>BEFORE</> may return null to signal the + Row-level triggers fired <literal>BEFORE</> can return null to signal the trigger manager to skip the rest of the operation for this row (i.e., subsequent triggers are not fired, and the <command>INSERT</>/<command>UPDATE</>/<command>DELETE</> does not occur @@ -2919,8 +2919,8 @@ RAISE EXCEPTION 'Nonexistent ID --> %', user_id; <para> The return value of a <literal>BEFORE</> or <literal>AFTER</> statement-level trigger or an <literal>AFTER</> row-level trigger is - always ignored; it may as well be null. However, any of these types of - triggers can still abort the entire operation by raising an error. + always ignored; it might as well be null. However, any of these types of + triggers might still abort the entire operation by raising an error. </para> <para> @@ -3037,7 +3037,7 @@ AFTER INSERT OR UPDATE OR DELETE ON emp original table for certain queries — often with vastly reduced run times. This technique is commonly used in Data Warehousing, where the tables - of measured or observed data (called fact tables) can be extremely large. + of measured or observed data (called fact tables) might be extremely large. <xref linkend="plpgsql-trigger-summary-example"> shows an example of a trigger procedure in <application>PL/pgSQL</application> that maintains a summary table for a fact table in a data warehouse. diff --git a/doc/src/sgml/plpython.sgml b/doc/src/sgml/plpython.sgml index d6f5aa3d96..8bc2f93b8f 100644 --- a/doc/src/sgml/plpython.sgml +++ b/doc/src/sgml/plpython.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/plpython.sgml,v 1.36 2006/10/23 18:10:31 petere Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/plpython.sgml,v 1.37 2007/01/31 20:56:18 momjian Exp $ --> <chapter id="plpython"> <title>PL/Python - Python Procedural Language</title> @@ -29,7 +29,7 @@ available as an <quote>untrusted</> language (meaning it does not offer any way of restricting what users can do in it). It has therefore been renamed to <literal>plpythonu</>. The trusted - variant <literal>plpython</> may become available again in future, + variant <literal>plpython</> might become available again in future, if a new secure execution mechanism is developed in Python. </para> @@ -401,7 +401,7 @@ $$ LANGUAGE plpythonu; </para> <para> - If <literal>TD["when"]</literal> is <literal>BEFORE</>, you may + If <literal>TD["when"]</literal> is <literal>BEFORE</>, you can return <literal>None</literal> or <literal>"OK"</literal> from the Python function to indicate the row is unmodified, <literal>"SKIP"</> to abort the event, or <literal>"MODIFY"</> to diff --git a/doc/src/sgml/pltcl.sgml b/doc/src/sgml/pltcl.sgml index 33e24fa0ea..9aa3f2d630 100644 --- a/doc/src/sgml/pltcl.sgml +++ b/doc/src/sgml/pltcl.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/pltcl.sgml,v 2.43 2007/01/30 22:29:23 momjian Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/pltcl.sgml,v 2.44 2007/01/31 20:56:18 momjian Exp $ --> <chapter id="pltcl"> <title>PL/Tcl - Tcl Procedural Language</title> @@ -39,12 +39,12 @@ provides no way to access internals of the database server or to gain OS-level access under the permissions of the <productname>PostgreSQL</productname> server process, as a C - function can do. Thus, unprivileged database users may be trusted + function can do. Thus, unprivileged database users can be trusted to use this language; it does not give them unlimited authority. </para> <para> The other notable implementation restriction is that Tcl functions - may not be used to create input/output functions for new data + cannot be used to create input/output functions for new data types. </para> <para> @@ -325,7 +325,7 @@ spi_exec -array C "SELECT * FROM pg_class" { PL/Tcl</></> </para> <para> - The query may use parameters, that is, placeholders for + The query can use parameters, that is, placeholders for values to be supplied whenever the plan is actually executed. In the query string, refer to parameters by the symbols <literal>$1</literal> ... <literal>$<replaceable>n</replaceable></literal>. @@ -417,7 +417,7 @@ $$ LANGUAGE pltcl; <listitem> <para> Doubles all occurrences of single quote and backslash characters - in the given string. This may be used to safely quote strings + in the given string. This can be used to safely quote strings that are to be inserted into SQL commands given to <function>spi_exec</function> or <function>spi_prepare</function>. @@ -726,9 +726,8 @@ CREATE TRIGGER trig_mytab_modcount BEFORE INSERT OR UPDATE ON mytab <title>Tcl Procedure Names</title> <para> - In <productname>PostgreSQL</productname>, one and the - same function name can be used for - different functions as long as the number of arguments or their types + In <productname>PostgreSQL</productname>, the same function name can be used for + different function definitions as long as the number of arguments or their types differ. Tcl, however, requires all procedure names to be distinct. PL/Tcl deals with this by making the internal Tcl procedure names contain the object diff --git a/doc/src/sgml/postgres.sgml b/doc/src/sgml/postgres.sgml index 4f55c2dcac..12a90dcec7 100644 --- a/doc/src/sgml/postgres.sgml +++ b/doc/src/sgml/postgres.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/postgres.sgml,v 1.80 2006/11/17 16:38:44 momjian Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/postgres.sgml,v 1.81 2007/01/31 20:56:18 momjian Exp $ --> <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook V4.2//EN" [ @@ -223,7 +223,7 @@ <partintro> <para> - This part contains assorted information that can be of use to + This part contains assorted information that might be of use to <productname>PostgreSQL</> developers. </para> </partintro> diff --git a/doc/src/sgml/problems.sgml b/doc/src/sgml/problems.sgml index b0f42a6923..0730b17a3f 100644 --- a/doc/src/sgml/problems.sgml +++ b/doc/src/sgml/problems.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/problems.sgml,v 2.27 2006/09/16 00:30:15 momjian Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/problems.sgml,v 2.28 2007/01/31 20:56:18 momjian Exp $ --> <sect1 id="bug-reporting"> <title>Bug Reporting Guidelines</title> @@ -228,7 +228,7 @@ If the function or the options do not exist then your version is more than old enough to warrant an upgrade. If you run a prepackaged version, such as RPMs, say so, including any - subversion the package may have. If you are talking about a CVS + subversion the package might have. If you are talking about a CVS snapshot, mention that, including its date and time. </para> diff --git a/doc/src/sgml/protocol.sgml b/doc/src/sgml/protocol.sgml index ef2ece938f..9f0059f8b2 100644 --- a/doc/src/sgml/protocol.sgml +++ b/doc/src/sgml/protocol.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/protocol.sgml,v 1.66 2006/09/06 20:40:47 tgl Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/protocol.sgml,v 1.67 2007/01/31 20:56:18 momjian Exp $ --> <chapter id="protocol"> <title>Frontend/Backend Protocol</title> @@ -9,7 +9,7 @@ The protocol is supported over <acronym>TCP/IP</acronym> and also over Unix-domain sockets. Port number 5432 has been registered with IANA as the customary TCP port number for servers supporting this protocol, but - in practice any non-privileged port number may be used. + in practice any non-privileged port number can be used. </para> <para> @@ -104,7 +104,7 @@ count) before attempting to process its contents. This allows easy recovery if an error is detected while processing the contents. In extreme situations (such as not having enough memory to buffer the - message), the receiver may use the byte count to determine how much + message), the receiver can use the byte count to determine how much input to skip before it resumes reading messages. </para> @@ -128,7 +128,7 @@ <firstterm>portals</>. A prepared statement represents the result of parsing, semantic analysis, and (optionally) planning of a textual query string. - A prepared statement is not necessarily ready to execute, because it may + A prepared statement is not necessarily ready to execute, because it might lack specific values for <firstterm>parameters</>. A portal represents a ready-to-execute or already-partially-executed statement, with any missing parameter values filled in. (For <command>SELECT</> statements, @@ -144,7 +144,7 @@ <firstterm>execute</> step that runs a portal's query. In the case of a query that returns rows (<command>SELECT</>, <command>SHOW</>, etc), the execute step can be told to fetch only - a limited number of rows, so that multiple execute steps may be needed + a limited number of rows, so that multiple execute steps might be needed to complete the operation. </para> @@ -170,7 +170,7 @@ the only supported formats are <quote>text</> and <quote>binary</>, but the protocol makes provision for future extensions. The desired format for any value is specified by a <firstterm>format code</>. - Clients may specify a format code for each transmitted parameter value + Clients can specify a format code for each transmitted parameter value and for each column of a query result. Text has format code zero, binary has format code one, and all other format codes are reserved for future definition. @@ -189,7 +189,7 @@ Binary representations for integers use network byte order (most significant byte first). For other data types consult the documentation or source code to learn about the binary representation. Keep in mind - that binary representations for complex data types may change across + that binary representations for complex data types might change across server versions; the text format is usually the more portable choice. </para> </sect2> @@ -379,8 +379,8 @@ <para> This message informs the frontend about the current (initial) setting of backend parameters, such as <xref - linkend="guc-client-encoding"> or <xref linkend="guc-datestyle">. - The frontend may ignore this message, or record the settings + linkend="guc-client-encoding"> or <xref linkend="guc-datestyle">. + The frontend can ignore this message, or record the settings for its future use; see <xref linkend="protocol-async"> for more details. The frontend should not respond to this message, but should continue listening for a ReadyForQuery @@ -393,7 +393,7 @@ <term>ReadyForQuery</term> <listitem> <para> - Start-up is completed. The frontend may now issue commands. + Start-up is completed. The frontend can now issue commands. </para> </listitem> </varlistentry> @@ -440,7 +440,7 @@ The backend then sends one or more response messages depending on the contents of the query command string, and finally a ReadyForQuery response message. ReadyForQuery - informs the frontend that it may safely send a new command. + informs the frontend that it can safely send a new command. (It is not actually necessary for the frontend to wait for ReadyForQuery before issuing another command, but the frontend must then take responsibility for figuring out what happens if the earlier @@ -526,7 +526,7 @@ <listitem> <para> Processing of the query string is complete. A separate - message is sent to indicate this because the query string may + message is sent to indicate this because the query string might contain multiple SQL commands. (CommandComplete marks the end of processing one SQL command, not the whole string.) ReadyForQuery will always be sent, whether processing @@ -577,7 +577,7 @@ In the event of an error, ErrorResponse is issued followed by ReadyForQuery. All further processing of the query string is aborted by ErrorResponse (even if more queries remained in it). Note that this - may occur partway through the sequence of messages generated by an + might occur partway through the sequence of messages generated by an individual query. </para> @@ -593,7 +593,7 @@ A frontend must be prepared to accept ErrorResponse and NoticeResponse messages whenever it is expecting any other type of message. See also <xref linkend="protocol-async"> concerning messages - that the backend may generate due to outside events. + that the backend might generate due to outside events. </para> <para> @@ -621,7 +621,7 @@ about data types of parameter placeholders, and the name of a destination prepared-statement object (an empty string selects the unnamed prepared statement). The response is - either ParseComplete or ErrorResponse. Parameter data types may be + either ParseComplete or ErrorResponse. Parameter data types can be specified by OID; if not given, the parser attempts to infer the data types in the same way as it would do for untyped literal string constants. @@ -695,7 +695,7 @@ <para> Query planning for named prepared-statement objects occurs when the Parse message is processed. If a query will be repeatedly executed with - different parameters, it may be beneficial to send a single Parse message + different parameters, it might be beneficial to send a single Parse message containing a parameterized query, followed by multiple Bind and Execute messages. This will avoid replanning the query on each execution. @@ -711,7 +711,7 @@ <note> <para> - Query plans generated from a parameterized query may be less + Query plans generated from a parameterized query might be less efficient than query plans generated from an equivalent query with actual parameter values substituted. The query planner cannot make decisions based on actual parameter values (for example, index selectivity) when @@ -877,7 +877,7 @@ FunctionCall message to the backend. The backend then sends one or more response messages depending on the results of the function call, and finally a ReadyForQuery response message. ReadyForQuery - informs the frontend that it may safely send a new query or + informs the frontend that it can safely send a new query or function call. </para> @@ -1080,7 +1080,7 @@ <para> At present, NotificationResponse can only be sent outside a transaction, and thus it will not occur in the middle of a - command-response series, though it may occur just before ReadyForQuery. + command-response series, though it might occur just before ReadyForQuery. It is unwise to design frontend logic that assumes that, however. Good practice is to be able to accept NotificationResponse at any point in the protocol. @@ -1092,7 +1092,7 @@ <title>Cancelling Requests in Progress</title> <para> - During the processing of a query, the frontend may request + During the processing of a query, the frontend might request cancellation of the query. The cancel request is not sent directly on the open connection to the backend for reasons of implementation efficiency: we don't want to have the backend @@ -1122,7 +1122,7 @@ </para> <para> - The cancellation signal may or may not have any effect — for + The cancellation signal might or might not have any effect — for example, if it arrives after the backend has finished processing the query, then it will have no effect. If the cancellation is effective, it results in the current command being terminated @@ -1144,7 +1144,7 @@ server and not across the regular frontend/backend communication link, it is possible for the cancel request to be issued by any process, not just the frontend whose query is to be canceled. - This may have some benefits of flexibility in building + This might provide additional flexibility when building multiple-process applications. It also introduces a security risk, in that unauthorized persons might try to cancel queries. The security risk is addressed by requiring a dynamically @@ -1164,7 +1164,7 @@ <para> In rare cases (such as an administrator-commanded database shutdown) - the backend may disconnect without any frontend request to do so. + the backend might disconnect without any frontend request to do so. In such cases the backend will attempt to send an error or notice message giving the reason for the disconnection before it closes the connection. </para> @@ -1187,7 +1187,7 @@ is being processed, the backend will probably finish the query before noticing the disconnection. If the query is outside any transaction block (<command>BEGIN</> ... <command>COMMIT</> - sequence) then its results may be committed before the + sequence) then its results might be committed before the disconnection is recognized. </para> </sect2> @@ -1211,7 +1211,7 @@ StartupMessage. The server then responds with a single byte containing <literal>S</> or <literal>N</>, indicating that it is willing or unwilling to perform <acronym>SSL</acronym>, - respectively. The frontend may close the connection at this point + respectively. The frontend might close the connection at this point if it is dissatisfied with the response. To continue after <literal>S</>, perform an <acronym>SSL</acronym> startup handshake (not described here, part of the <acronym>SSL</acronym> @@ -1228,18 +1228,18 @@ response to SSLRequest from the server. This would only occur if the server predates the addition of <acronym>SSL</acronym> support to <productname>PostgreSQL</>. In this case the connection must - be closed, but the frontend may choose to open a fresh connection + be closed, but the frontend might choose to open a fresh connection and proceed without requesting <acronym>SSL</acronym>. </para> <para> - An initial SSLRequest may also be used in a connection that is being + An initial SSLRequest can also be used in a connection that is being opened to send a CancelRequest message. </para> <para> While the protocol itself does not provide a way for the server to - force <acronym>SSL</acronym> encryption, the administrator may + force <acronym>SSL</acronym> encryption, the administrator can configure the server to reject unencrypted sessions as a byproduct of authentication checking. </para> @@ -1333,13 +1333,13 @@ characters that don't fit into your fixed-size buffer. <para> This section describes the detailed format of each message. Each is marked to -indicate that it may be sent by a frontend (F), a backend (B), or both +indicate that it can be sent by a frontend (F), a backend (B), or both (F & B). Notice that although each message includes a byte count at the beginning, the message format is defined so that the message end can be found without reference to the byte count. This aids validity checking. (The CopyData message is an exception, because it forms part of a data stream; the contents -of any individual CopyData message may not be interpretable on their own.) +of any individual CopyData message cannot be interpretable on their own.) </para> <variablelist> @@ -2155,7 +2155,7 @@ CopyData (F & B) <para> Data that forms part of a <command>COPY</command> data stream. Messages sent from the backend will always correspond to single data rows, - but messages sent by frontends may divide the data stream + but messages sent by frontends might divide the data stream arbitrarily. </para> </listitem> @@ -2591,7 +2591,7 @@ ErrorResponse (B) </varlistentry> </variablelist> The message body consists of one or more identified fields, - followed by a zero byte as a terminator. Fields may appear in + followed by a zero byte as a terminator. Fields can appear in any order. For each field there is the following: <variablelist> <varlistentry> @@ -2604,7 +2604,7 @@ ErrorResponse (B) the message terminator and no string follows. The presently defined field types are listed in <xref linkend="protocol-error-fields">. - Since more field types may be added in future, + Since more field types might be added in future, frontends should silently ignore fields of unrecognized type. </para> @@ -2969,7 +2969,7 @@ NoticeResponse (B) </varlistentry> </variablelist> The message body consists of one or more identified fields, - followed by a zero byte as a terminator. Fields may appear in + followed by a zero byte as a terminator. Fields can appear in any order. For each field there is the following: <variablelist> <varlistentry> @@ -2982,7 +2982,7 @@ NoticeResponse (B) the message terminator and no string follows. The presently defined field types are listed in <xref linkend="protocol-error-fields">. - Since more field types may be added in future, + Since more field types might be added in future, frontends should silently ignore fields of unrecognized type. </para> @@ -3107,7 +3107,7 @@ ParameterDescription (B) <listitem> <para> The number of parameters used by the statement - (may be zero). + (can be zero). </para> </listitem> </varlistentry> @@ -3240,7 +3240,7 @@ Parse (F) <listitem> <para> The number of parameter data types specified - (may be zero). Note that this is not an indication of + (can be zero). Note that this is not an indication of the number of parameters that might appear in the query string, only the number that the frontend wants to prespecify types for. @@ -3513,7 +3513,7 @@ RowDescription (B) </term> <listitem> <para> - Specifies the number of fields in a row (may be zero). + Specifies the number of fields in a row (can be zero). </para> </listitem> </varlistentry> @@ -3726,7 +3726,7 @@ StartupMessage (F) </variablelist> In addition to the above, any run-time parameter that can be - set at backend start time may be listed. Such settings + set at backend start time might be listed. Such settings will be applied during backend start (after parsing the command-line options if any). The values will act as session defaults. @@ -3829,7 +3829,7 @@ Terminate (F) <title>Error and Notice Message Fields</title> <para> -This section describes the fields that may appear in ErrorResponse and +This section describes the fields that can appear in ErrorResponse and NoticeResponse messages. Each field type has a single-byte identification token. Note that any given field type should appear at most once per message. @@ -3885,7 +3885,7 @@ message. <listitem> <para> Detail: an optional secondary error message carrying more - detail about the problem. May run to multiple lines. + detail about the problem. Might run to multiple lines. </para> </listitem> </varlistentry> @@ -3899,7 +3899,7 @@ message. Hint: an optional suggestion what to do about the problem. This is intended to differ from Detail in that it offers advice (potentially inappropriate) rather than hard facts. - May run to multiple lines. + Might run to multiple lines. </para> </listitem> </varlistentry> @@ -4030,7 +4030,7 @@ PasswordMessage now has a type byte. <para> ErrorResponse and NoticeResponse ('<literal>E</>' and '<literal>N</>') -messages now contain multiple fields, from which the client code may +messages now contain multiple fields, from which the client code can assemble an error message of the desired level of verbosity. Note that individual fields will typically not end with a newline, whereas the single string sent in the older protocol always did. @@ -4055,7 +4055,7 @@ message types Parse, Bind, Execute, Describe, Close, Flush, and Sync, and the backend message types ParseComplete, BindComplete, PortalSuspended, ParameterDescription, NoData, and CloseComplete. Existing clients do not have to concern themselves with this sub-protocol, but making use of it -may allow improvements in performance or functionality. +might allow improvements in performance or functionality. </para> <para> @@ -4098,7 +4098,7 @@ the backend. <para> The NotificationResponse ('<literal>A</>') message has an additional string -field, which is presently empty but may someday carry additional data passed +field, which is presently empty but might someday carry additional data passed from the <command>NOTIFY</command> event sender. </para> diff --git a/doc/src/sgml/queries.sgml b/doc/src/sgml/queries.sgml index c427303db3..13288a627a 100644 --- a/doc/src/sgml/queries.sgml +++ b/doc/src/sgml/queries.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/queries.sgml,v 1.41 2007/01/09 16:59:20 tgl Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/queries.sgml,v 1.42 2007/01/31 20:56:18 momjian Exp $ --> <chapter id="queries"> <title>Queries</title> @@ -116,11 +116,11 @@ SELECT random(); FROM <replaceable>table_reference</replaceable> <optional>, <replaceable>table_reference</replaceable> <optional>, ...</optional></optional> </synopsis> - A table reference may be a table name (possibly schema-qualified), + A table reference can be a table name (possibly schema-qualified), or a derived table such as a subquery, a table join, or complex combinations of these. If more than one table reference is listed in the <literal>FROM</> clause they are cross-joined (see below) - to form the intermediate virtual table that may then be subject to + to form the intermediate virtual table that can then be subject to transformations by the <literal>WHERE</>, <literal>GROUP BY</>, and <literal>HAVING</> clauses and is finally the result of the overall table expression. @@ -350,8 +350,8 @@ FROM <replaceable>table_reference</replaceable> <optional>, <replaceable>table_r <para> Joins of all types can be chained together or nested: either or both of <replaceable>T1</replaceable> and - <replaceable>T2</replaceable> may be joined tables. Parentheses - may be used around <literal>JOIN</> clauses to control the join + <replaceable>T2</replaceable> might be joined tables. Parentheses + can be used around <literal>JOIN</> clauses to control the join order. In the absence of parentheses, <literal>JOIN</> clauses nest left-to-right. </para> @@ -623,7 +623,7 @@ FROM (VALUES ('anne', 'smith'), ('bob', 'jones'), ('joe', 'blow')) of either base data types (scalar types) or composite data types (table rows). They are used like a table, view, or subquery in the <literal>FROM</> clause of a query. Columns returned by table - functions may be included in <literal>SELECT</>, + functions can be included in <literal>SELECT</>, <literal>JOIN</>, or <literal>WHERE</> clauses in the same manner as a table, view, or subquery column. </para> @@ -636,8 +636,8 @@ FROM (VALUES ('anne', 'smith'), ('bob', 'jones'), ('joe', 'blow')) </para> <para> - A table function may be aliased in the <literal>FROM</> clause, - but it also may be left unaliased. If a function is used in the + A table function can be aliased in the <literal>FROM</> clause, + but it also can be left unaliased. If a function is used in the <literal>FROM</> clause with no alias, the function name is used as the resulting table name. </para> @@ -788,7 +788,7 @@ SELECT ... FROM fdt WHERE EXISTS (SELECT c1 FROM t2 WHERE c2 > fdt.c1) <para> After passing the <literal>WHERE</> filter, the derived input - table may be subject to grouping, using the <literal>GROUP BY</> + table might be subject to grouping, using the <literal>GROUP BY</> clause, and elimination of group rows using the <literal>HAVING</> clause. </para> @@ -877,7 +877,7 @@ SELECT product_id, p.name, (sum(s.units) * p.price) AS sales <literal>p.name</literal>, and <literal>p.price</literal> must be in the <literal>GROUP BY</> clause since they are referenced in the query select list. (Depending on how exactly the products - table is set up, name and price may be fully dependent on the + table is set up, name and price might be fully dependent on the product ID, so the additional groupings could theoretically be unnecessary, but this is not implemented yet.) The column <literal>s.units</> does not have to be in the <literal>GROUP @@ -1070,7 +1070,7 @@ SELECT a AS value, b + c AS sum FROM ... </indexterm> <para> - After the select list has been processed, the result table may + After the select list has been processed, the result table can optionally be subject to the elimination of duplicate rows. The <literal>DISTINCT</literal> key word is written directly after <literal>SELECT</literal> to specify this: @@ -1234,7 +1234,7 @@ SELECT a, b FROM table1 ORDER BY a + b, c; </programlisting> When more than one expression is specified, the later values are used to sort rows that are equal according to the - earlier values. Each expression may be followed by an optional + earlier values. Each expression can be followed by an optional <literal>ASC</> or <literal>DESC</> keyword to set the sort direction to ascending or descending. <literal>ASC</> order is the default. Ascending order puts smaller values first, where @@ -1342,7 +1342,7 @@ SELECT <replaceable>select_list</replaceable> When using <literal>LIMIT</>, it is important to use an <literal>ORDER BY</> clause that constrains the result rows into a unique order. Otherwise you will get an unpredictable subset of - the query's rows. You may be asking for the tenth through + the query's rows. You might be asking for the tenth through twentieth rows, but tenth through twentieth in what ordering? The ordering is unknown, unless you specified <literal>ORDER BY</>. </para> @@ -1364,7 +1364,7 @@ SELECT <replaceable>select_list</replaceable> <para> The rows skipped by an <literal>OFFSET</> clause still have to be computed inside the server; therefore a large <literal>OFFSET</> - can be inefficient. + might be inefficient. </para> </sect1> diff --git a/doc/src/sgml/query.sgml b/doc/src/sgml/query.sgml index d19c074529..0bd51c92d9 100644 --- a/doc/src/sgml/query.sgml +++ b/doc/src/sgml/query.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/query.sgml,v 1.48 2006/10/21 23:12:57 tgl Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/query.sgml,v 1.49 2007/01/31 20:56:18 momjian Exp $ --> <chapter id="tutorial-sql"> <title>The <acronym>SQL</acronym> Language</title> @@ -134,7 +134,7 @@ CREATE TABLE weather ( </para> <para> - White space (i.e., spaces, tabs, and newlines) may be used freely + White space (i.e., spaces, tabs, and newlines) can be used freely in SQL commands. That means you can type the command aligned differently than above, or even all on one line. Two dashes (<quote><literal>--</literal></quote>) introduce comments. @@ -151,7 +151,7 @@ CREATE TABLE weather ( a type for storing single precision floating-point numbers. <type>date</type> should be self-explanatory. (Yes, the column of type <type>date</type> is also named <literal>date</literal>. - This may be convenient or confusing — you choose.) + This might be convenient or confusing — you choose.) </para> <para> @@ -817,7 +817,7 @@ SELECT city, max(temp_lo) You can update existing rows using the <command>UPDATE</command> command. Suppose you discover the temperature readings are - all off by 2 degrees after November 28. You may correct the + all off by 2 degrees after November 28. You can correct the data as follows: <programlisting> diff --git a/doc/src/sgml/reference.sgml b/doc/src/sgml/reference.sgml index 9b3cbda575..06c6c4a21d 100644 --- a/doc/src/sgml/reference.sgml +++ b/doc/src/sgml/reference.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/reference.sgml,v 1.61 2007/01/23 05:07:17 tgl Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/reference.sgml,v 1.62 2007/01/31 20:56:18 momjian Exp $ --> <part id="reference"> <title>Reference</title> @@ -9,7 +9,7 @@ length an authoritative, complete, and formal summary about their respective subjects. More information about the use of <productname>PostgreSQL</productname>, in narrative, tutorial, or - example form, may be found in other parts of this book. See the + example form, can be found in other parts of this book. See the cross-references listed on each reference page. </para> @@ -159,7 +159,7 @@ This part contains reference information for <productname>PostgreSQL</productname> client applications and utilities. Not all of these commands are of general utility, some - may require special privileges. The common feature of these + might require special privileges. The common feature of these applications is that they can be run on any host, independent of where the database server resides. </para> diff --git a/doc/src/sgml/regress.sgml b/doc/src/sgml/regress.sgml index 073b8e6143..e28f876f10 100644 --- a/doc/src/sgml/regress.sgml +++ b/doc/src/sgml/regress.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/regress.sgml,v 1.55 2006/09/16 00:30:15 momjian Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/regress.sgml,v 1.56 2007/01/31 20:56:18 momjian Exp $ --> <chapter id="regress"> <title id="regress-title">Regression Tests</title> @@ -84,7 +84,7 @@ gmake check If you have configured <productname>PostgreSQL</productname> to install into a location where an older <productname>PostgreSQL</productname> installation already exists, and you perform <literal>gmake check</> - before installing the new version, you may find that the tests fail + before installing the new version, you might find that the tests fail because the new programs try to use the already-installed shared libraries. (Typical symptoms are complaints about undefined symbols.) If you wish to run the tests before overwriting the old installation, @@ -99,7 +99,7 @@ gmake check scripts, which means forty processes: there's a server process and a <application>psql</> process for each test script. So if your system enforces a per-user limit on the number of processes, - make sure this limit is at least fifty or so, else you may get + make sure this limit is at least fifty or so, else you might get random-seeming failures in the parallel test. If you are not in a position to raise the limit, you can cut down the degree of parallelism by setting the <literal>MAX_CONNECTIONS</> parameter. For example, @@ -161,7 +161,7 @@ gmake installcheck generated on a reference system, so the results are sensitive to small system differences. When a test is reported as <quote>failed</quote>, always examine the differences between - expected and actual results; you may well find that the + expected and actual results; you might find that the differences are not significant. Nonetheless, we still strive to maintain accurate reference files across all supported platforms, so it can be expected that all tests pass. @@ -193,7 +193,7 @@ gmake installcheck Some of the regression tests involve intentional invalid input values. Error messages can come from either the <productname>PostgreSQL</productname> code or from the host - platform system routines. In the latter case, the messages may + platform system routines. In the latter case, the messages can vary between platforms, but should reflect similar information. These differences in messages will result in a <quote>failed</quote> regression test that can be validated by @@ -207,7 +207,7 @@ gmake installcheck <para> If you run the tests against an already-installed server that was initialized with a collation-order locale other than C, then - there may be differences due to sort order and follow-up + there might be differences due to sort order and follow-up failures. The regression test suite is set up to handle this problem by providing alternative result files that together are known to handle a large number of locales. diff --git a/doc/src/sgml/release.sgml b/doc/src/sgml/release.sgml index bf4fd36ab4..ad458d3bd1 100644 --- a/doc/src/sgml/release.sgml +++ b/doc/src/sgml/release.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/release.sgml,v 1.491 2007/01/06 15:19:45 momjian Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/release.sgml,v 1.492 2007/01/31 20:56:18 momjian Exp $ --> <!-- Typical markup: @@ -504,7 +504,7 @@ do it for earlier branch release files. </para> <para> - This may eliminate the need to set unrealistically small + This might eliminate the need to set unrealistically small values of <link linkend="guc-random-page-cost"><varname>random_page_cost</></link>. If you have been using a very small <varname>random_page_cost</>, @@ -989,7 +989,7 @@ do it for earlier branch release files. <para> On platforms where it is expensive to update the <application>ps</> - display, it may be worthwhile to turn this off and rely solely on + display, it might be worthwhile to turn this off and rely solely on <structname>pg_stat_activity</> for status information. </para> </listitem> @@ -1270,7 +1270,7 @@ do it for earlier branch release files. <para> This prevents surprising behavior due to multiple evaluation of a <literal>volatile</> function (such as <function>random()</> - or <function>nextval()</>). It may cause performance + or <function>nextval()</>). It might cause performance degradation in the presence of functions that are unnecessarily marked as <literal>volatile</>. </para> @@ -2966,7 +2966,7 @@ compilers (Hiroshi Saito)</para></listitem> <para> Full security against the SQL-injection attacks described in - CVE-2006-2313 and CVE-2006-2314 may require changes in application + CVE-2006-2313 and CVE-2006-2314 might require changes in application code. If you have applications that embed untrustworthy strings into SQL commands, you should examine them as soon as possible to ensure that they are using recommended escaping techniques. In @@ -2998,7 +2998,7 @@ literals. By default, <literal>\'</> is rejected only when GB18030, or UHC), which is the scenario in which SQL injection is possible. A new configuration parameter <varname>backslash_quote</> is available to adjust this behavior when needed. Note that full security against -CVE-2006-2314 may require client-side changes; the purpose of +CVE-2006-2314 might require client-side changes; the purpose of <varname>backslash_quote</> is in part to make it obvious that insecure clients are insecure. </para></listitem> @@ -3265,7 +3265,7 @@ to ensure that <application>plperl</> won't change the locale later</para> <para>This fixes a problem that occurred if the <application>postmaster</> was started with environment variables specifying a different locale than what <application>initdb</> had been told. Under these conditions, any use of -<application>plperl</> was likely to lead to corrupt indexes. You may need +<application>plperl</> was likely to lead to corrupt indexes. You might need <command>REINDEX</> to fix existing indexes on textual columns if this has happened to you.</para></listitem> @@ -3663,7 +3663,7 @@ DISTINCT query</para></listitem> </para> <para> - It may be necessary to set <varname>add_missing_from</> to true + It might be necessary to set <varname>add_missing_from</> to true in order to load an existing dump file, if the dump contains any views or rules created using the implicit-<literal>FROM</> syntax. This should be a one-time annoyance, because @@ -3885,7 +3885,7 @@ psql -t -f fixseq.sql db1 | psql -e db1 <listitem> <para> - <command>CREATE LANGUAGE</> may ignore the provided arguments + <command>CREATE LANGUAGE</> can ignore the provided arguments in favor of information from <structname>pg_pltemplate</> (Tom) </para> @@ -5724,7 +5724,7 @@ Wieland)</para></listitem> <para> Full security against the SQL-injection attacks described in - CVE-2006-2313 and CVE-2006-2314 may require changes in application + CVE-2006-2313 and CVE-2006-2314 might require changes in application code. If you have applications that embed untrustworthy strings into SQL commands, you should examine them as soon as possible to ensure that they are using recommended escaping techniques. In @@ -5756,7 +5756,7 @@ literals. By default, <literal>\'</> is rejected only when GB18030, or UHC), which is the scenario in which SQL injection is possible. A new configuration parameter <varname>backslash_quote</> is available to adjust this behavior when needed. Note that full security against -CVE-2006-2314 may require client-side changes; the purpose of +CVE-2006-2314 might require client-side changes; the purpose of <varname>backslash_quote</> is in part to make it obvious that insecure clients are insecure. </para></listitem> @@ -5962,7 +5962,7 @@ to ensure that <application>plperl</> won't change the locale later</para> <para>This fixes a problem that occurred if the <application>postmaster</> was started with environment variables specifying a different locale than what <application>initdb</> had been told. Under these conditions, any use of -<application>plperl</> was likely to lead to corrupt indexes. You may need +<application>plperl</> was likely to lead to corrupt indexes. You might need <command>REINDEX</> to fix existing indexes on textual columns if this has happened to you.</para></listitem> @@ -6213,7 +6213,7 @@ code</para></listitem> It is strongly recommended that all installations repair these errors, either by initdb or by following the manual repair procedure given below. The errors at least allow unprivileged database users to crash - their server process, and may allow unprivileged users to gain the + their server process, and might allow unprivileged users to gain the privileges of a database superuser. </para> @@ -6882,8 +6882,7 @@ typedefs (Michael)</para></listitem> behavior across all platforms. In most cases, there should be little noticeable difference in time zone behavior, except that the time zone names used by <command>SET</>/<command>SHOW</> - <varname>TimeZone</> may - be different from what your platform provides. + <varname>TimeZone</> might be different from what your platform provides. </para> </listitem> @@ -7312,7 +7311,7 @@ typedefs (Michael)</para></listitem> Some logging-related configuration parameters could formerly be adjusted by ordinary users, but only in the <quote>more verbose</> direction. They are now treated more strictly: only superusers can set them. - However, a superuser may use <command>ALTER USER</> to provide per-user + However, a superuser can use <command>ALTER USER</> to provide per-user settings of these values for non-superusers. Also, it is now possible for superusers to set values of superuser-only configuration parameters via <literal>PGOPTIONS</>. @@ -9011,7 +9010,7 @@ ANYARRAY</para></listitem> <para> Full security against the SQL-injection attacks described in - CVE-2006-2313 and CVE-2006-2314 may require changes in application + CVE-2006-2313 and CVE-2006-2314 might require changes in application code. If you have applications that embed untrustworthy strings into SQL commands, you should examine them as soon as possible to ensure that they are using recommended escaping techniques. In @@ -9043,7 +9042,7 @@ literals. By default, <literal>\'</> is rejected only when GB18030, or UHC), which is the scenario in which SQL injection is possible. A new configuration parameter <varname>backslash_quote</> is available to adjust this behavior when needed. Note that full security against -CVE-2006-2314 may require client-side changes; the purpose of +CVE-2006-2314 might require client-side changes; the purpose of <varname>backslash_quote</> is in part to make it obvious that insecure clients are insecure. </para></listitem> @@ -9196,7 +9195,7 @@ to ensure that <application>plperl</> won't change the locale later</para> <para>This fixes a problem that occurred if the <application>postmaster</> was started with environment variables specifying a different locale than what <application>initdb</> had been told. Under these conditions, any use of -<application>plperl</> was likely to lead to corrupt indexes. You may need +<application>plperl</> was likely to lead to corrupt indexes. You might need <command>REINDEX</> to fix existing indexes on textual columns if this has happened to you.</para></listitem> @@ -9382,7 +9381,7 @@ code</para></listitem> It is strongly recommended that all installations repair these errors, either by initdb or by following the manual repair procedures given below. The errors at least allow unprivileged database users to crash - their server process, and may allow unprivileged users to gain the + their server process, and might allow unprivileged users to gain the privileges of a database superuser. </para> @@ -9806,7 +9805,7 @@ names from outer query levels. <para> A dump/restore is not required for those running 7.4.X. However, - it may be advisable as the easiest method of incorporating fixes for + it might be advisable as the easiest method of incorporating fixes for two errors that have been found in the initial contents of 7.4.X system catalogs. A dump/initdb/reload sequence using 7.4.2's initdb will automatically correct these problems. @@ -10360,7 +10359,7 @@ DROP SCHEMA information_schema CASCADE; <listitem> <para> Inner joins using the explicit <literal>JOIN</literal> syntax - may behave differently because they are now better + might behave differently because they are now better optimized. </para> </listitem> @@ -11327,7 +11326,7 @@ DROP SCHEMA information_schema CASCADE; <listitem> <para> - Arrays may now be specified as <literal>ARRAY[1,2,3]</literal>, + Arrays can now be specified as <literal>ARRAY[1,2,3]</literal>, <literal>ARRAY[['a','b'],['c','d']]</literal>, or <literal>ARRAY[ARRAY[ARRAY[2]]]</literal> (Joe) </para> @@ -12025,7 +12024,7 @@ DROP SCHEMA information_schema CASCADE; <para> Full security against the SQL-injection attacks described in - CVE-2006-2313 and CVE-2006-2314 may require changes in application + CVE-2006-2313 and CVE-2006-2314 might require changes in application code. If you have applications that embed untrustworthy strings into SQL commands, you should examine them as soon as possible to ensure that they are using recommended escaping techniques. In @@ -12057,7 +12056,7 @@ literals. By default, <literal>\'</> is rejected only when GB18030, or UHC), which is the scenario in which SQL injection is possible. A new configuration parameter <varname>backslash_quote</> is available to adjust this behavior when needed. Note that full security against -CVE-2006-2314 may require client-side changes; the purpose of +CVE-2006-2314 might require client-side changes; the purpose of <varname>backslash_quote</> is in part to make it obvious that insecure clients are insecure. </para></listitem> @@ -12190,7 +12189,7 @@ to ensure that <application>plperl</> won't change the locale later</para> <para>This fixes a problem that occurred if the <application>postmaster</> was started with environment variables specifying a different locale than what <application>initdb</> had been told. Under these conditions, any use of -<application>plperl</> was likely to lead to corrupt indexes. You may need +<application>plperl</> was likely to lead to corrupt indexes. You might need <command>REINDEX</> to fix existing indexes on textual columns if this has happened to you.</para></listitem> @@ -12345,7 +12344,7 @@ the variable is of pass-by-reference type</para></listitem> It is strongly recommended that all installations repair this error, either by initdb or by following the manual repair procedure given below. The error at least allows unprivileged database users to crash - their server process, and may allow unprivileged users to gain the + their server process, and might allow unprivileged users to gain the privileges of a database superuser. </para> @@ -12929,7 +12928,7 @@ operations on bytea columns (Joe)</para></listitem> A dump/restore is <emphasis>not</emphasis> required for those running version 7.3. However, it should be noted that the main <productname>PostgreSQL</productname> interface library, libpq, - has a new major version number for this release, which may require + has a new major version number for this release, which might require recompilation of client code in certain cases. </para> </sect2> @@ -13165,7 +13164,7 @@ operations on bytea columns (Joe)</para></listitem> <para> <command>COPY</command> no longer considers missing trailing columns to be null. All columns need to be specified. - (However, one may achieve a similar effect by specifying a + (However, one can achieve a similar effect by specifying a column list in the <command>COPY</command> command.) </para> </listitem> @@ -14066,7 +14065,7 @@ since <productname>PostgreSQL</productname> 7.1. <listitem> <para> The semantics of the <command>VACUUM</command> command have - changed in this release. You may wish to update your + changed in this release. You might wish to update your maintenance procedures accordingly. </para> </listitem> @@ -14661,7 +14660,7 @@ previous releases of <productname>PostgreSQL</productname> have forced all data modifications to disk before each transaction commit. With WAL, only one log file must be flushed to disk, greatly improving performance. If you have been using -F in previous releases to -disable disk flushes, you may want to consider discontinuing its use. +disable disk flushes, you might want to consider discontinuing its use. </para> </listitem> </varlistentry> @@ -14702,7 +14701,7 @@ outer join syntax. The previous C function manager did not handle null values properly, nor did it support 64-bit <acronym>CPU</acronym>'s (Alpha). The new function manager does. You can continue using your old custom -functions, but you may want to rewrite them in the future to use the new +functions, but you might want to rewrite them in the future to use the new function manager call interface. </para> </listitem> @@ -15175,7 +15174,7 @@ ecpg changes (Michael) A dump/restore using <application>pg_dump</application> is required for those wishing to migrate data from any previous release of <productname>PostgreSQL</productname>. - For those upgrading from 6.5.*, you may instead use + For those upgrading from 6.5.*, you can instead use <application>pg_upgrade</application> to upgrade to this release; however, a full dump/reload installation is always the most robust method for upgrades. @@ -15196,7 +15195,7 @@ ecpg changes (Michael) ease the transition by allowing <productname>PostgreSQL</productname> to recognize the deprecated type names and translate them to the new type - names, this mechanism may not be completely transparent to + names, this mechanism cannot be completely transparent to your existing application. </para> </listitem> @@ -15208,8 +15207,8 @@ ecpg changes (Michael) decreased query times as the optimizer makes a better choice for the preferred plan. However, in a small number of cases, usually involving pathological distributions of data, your - query times may go up. If you are dealing with large amounts - of data, you may want to check your queries to verify + query times might go up. If you are dealing with large amounts + of data, you might want to check your queries to verify performance. </para> </listitem> @@ -16690,7 +16689,7 @@ Better identify tcl and tk libs and includes(Bruce) <listitem> <para> Socket interface for client/server connection. This is the default now - so you may need to start <application>postmaster</application> with the + so you might need to start <application>postmaster</application> with the <option>-i</option> flag. </para> </listitem> @@ -16726,7 +16725,7 @@ Better identify tcl and tk libs and includes(Bruce) mention that without subselects, SQL is a very limited language. Subselects are a major feature, and you should review your code for places where subselects provide a better solution for your queries. I - think you will find that there are more uses for subselects than you may + think you will find that there are more uses for subselects than you might think. Vadim has put us on the big SQL map with subselects, and fully functional ones too. The only thing you can't do with subselects is to use them in the target list. @@ -16741,7 +16740,7 @@ Better identify tcl and tk libs and includes(Bruce) Third, <type>char()</type> fields will now allow faster access than <type>varchar()</type> or <type>text</type>. Specifically, the <type>text</> and <type>varchar()</type> have a penalty for access to any columns after the first column of this type. <type>char()</type> used to also - have this access penalty, but it no longer does. This may suggest that + have this access penalty, but it no longer does. This might suggest that you redesign some of your tables, especially if you have short character columns that you have defined as <type>varchar()</type> or <type>text</type>. This and other changes make 6.3 even faster than earlier releases. @@ -17290,7 +17289,7 @@ optimizer which uses <firstterm>genetic</firstterm> The interpretation of array specifiers (the curly braces around atomic values) appears to have changed sometime after the original regression tests were generated. The current <filename>./expected/*.out</filename> files reflect this - new interpretation, which may not be correct! + new interpretation, which might not be correct! </para> <para> @@ -18004,7 +18003,7 @@ Incompatible changes: * float literals (eg. 3.14) are now of type float4 (instead of float8 in previous releases); you might have to do typecasting if you depend on it being of type float8. If you neglect to do the typecasting and you assign - a float literal to a field of type float8, you may get incorrect values + a float literal to a field of type float8, you might get incorrect values stored! * LIBPQ has been totally revamped so that frontend applications can connect to multiple backends diff --git a/doc/src/sgml/rowtypes.sgml b/doc/src/sgml/rowtypes.sgml index 36f468e6ac..53ebba716e 100644 --- a/doc/src/sgml/rowtypes.sgml +++ b/doc/src/sgml/rowtypes.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/rowtypes.sgml,v 2.7 2007/01/30 22:29:23 momjian Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/rowtypes.sgml,v 2.8 2007/01/31 20:56:18 momjian Exp $ --> <sect1 id="rowtypes"> <title>Composite Types</title> @@ -99,7 +99,7 @@ CREATE TABLE inventory_item ( <para> To write a composite value as a literal constant, enclose the field - values within parentheses and separate them by commas. You may put double + values within parentheses and separate them by commas. You can put double quotes around any field value, and must do so if it contains commas or parentheses. (More details appear below.) Thus, the general format of a composite constant is the following: @@ -133,7 +133,7 @@ CREATE TABLE inventory_item ( </para> <para> - The <literal>ROW</literal> expression syntax may also be used to + The <literal>ROW</literal> expression syntax can also be used to construct composite values. In most cases this is considerably simpler to use than the string-literal syntax, since you don't have to worry about multiple layers of quoting. We already used this @@ -252,7 +252,7 @@ INSERT INTO mytab (complex_col.r, complex_col.i) VALUES(1.1, 2.2); The decoration consists of parentheses (<literal>(</> and <literal>)</>) around the whole value, plus commas (<literal>,</>) between adjacent items. Whitespace outside the parentheses is ignored, but within the - parentheses it is considered part of the field value, and may or may not be + parentheses it is considered part of the field value, and might or might not be significant depending on the input conversion rules for the field data type. For example, in <programlisting> @@ -263,7 +263,7 @@ INSERT INTO mytab (complex_col.r, complex_col.i) VALUES(1.1, 2.2); </para> <para> - As shown previously, when writing a composite value you may write double + As shown previously, when writing a composite value you can write double quotes around any individual field value. You <emphasis>must</> do so if the field value would otherwise confuse the composite-value parser. In particular, fields containing @@ -309,7 +309,7 @@ INSERT ... VALUES (E'("\\"\\\\")'); with a data type whose input routine also treated backslashes specially, <type>bytea</> for example, we might need as many as eight backslashes in the command to get one backslash into the stored composite field.) - Dollar quoting (see <xref linkend="sql-syntax-dollar-quoting">) may be + Dollar quoting (see <xref linkend="sql-syntax-dollar-quoting">) can be used to avoid the need to double backslashes. </para> </note> diff --git a/doc/src/sgml/rules.sgml b/doc/src/sgml/rules.sgml index 8ee30a63b4..5531ae35d5 100644 --- a/doc/src/sgml/rules.sgml +++ b/doc/src/sgml/rules.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/rules.sgml,v 1.48 2006/12/27 16:07:36 tgl Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/rules.sgml,v 1.49 2007/01/31 20:56:18 momjian Exp $ --> <chapter id="rules"> <title>The Rule System</title> @@ -1807,7 +1807,7 @@ GRANT SELECT ON phone_number TO secretary; the originally given query will be executed, and its command status will be returned as usual. (But note that if there were any conditional <literal>INSTEAD</> rules, the negation of their qualifications - will have been added to the original query. This may reduce the + will have been added to the original query. This might reduce the number of rows it processes, and if so the reported status will be affected.) </para> diff --git a/doc/src/sgml/runtime.sgml b/doc/src/sgml/runtime.sgml index 4eaf2bab59..35c04257dc 100644 --- a/doc/src/sgml/runtime.sgml +++ b/doc/src/sgml/runtime.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/runtime.sgml,v 1.374 2006/11/25 22:44:48 petere Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/runtime.sgml,v 1.375 2007/01/31 20:56:19 momjian Exp $ --> <chapter Id="runtime"> <title>Operating System Environment</title> @@ -338,9 +338,9 @@ FATAL: could not create TCP/IP listen socket This usually means just what it suggests: you tried to start another server on the same port where one is already running. However, if the kernel error message is not <computeroutput>Address - already in use</computeroutput> or some variant of that, there may + already in use</computeroutput> or some variant of that, there might be a different problem. For example, trying to start a server - on a reserved port number may draw something like: + on a reserved port number might draw something like: <screen> $ <userinput>postgres -p 666</userinput> LOG: could not bind IPv4 socket: Permission denied @@ -363,7 +363,7 @@ DETAIL: Failed system call was shmget(key=5440001, size=4011376640, 03600). can try starting the server with a smaller-than-normal number of buffers (<xref linkend="guc-shared-buffers">). You will eventually want to reconfigure your kernel to increase the allowed shared memory - size. You may also see this message when trying to start multiple + size. You might also see this message when trying to start multiple servers on the same machine, if their total space requested exceeds the kernel limit. </para> @@ -378,7 +378,7 @@ DETAIL: Failed system call was semget(5440126, 17, 03600). space. It means your kernel's limit on the number of <systemitem class="osname">System V</> semaphores is smaller than the number <productname>PostgreSQL</productname> wants to create. As above, - you may be able to work around the problem by starting the + you might be able to work around the problem by starting the server with a reduced number of allowed connections (<xref linkend="guc-max-connections">), but you'll eventually want to increase the kernel limit. @@ -442,7 +442,7 @@ psql: could not connect to server: No such file or directory connection request and rejected it. That case will produce a different message, as shown in <xref linkend="client-authentication-problems">.) Other error messages - such as <computeroutput>Connection timed out</computeroutput> may + such as <computeroutput>Connection timed out</computeroutput> might indicate more fundamental problems, like lack of network connectivity. </para> @@ -861,7 +861,7 @@ options SEMMAP=256 </para> <para> - Older distributions may not have the <command>sysctl</command> program, + Older distributions might not have the <command>sysctl</command> program, but equivalent changes can be made by manipulating the <filename>/proc</filename> file system: <screen> @@ -900,7 +900,7 @@ sysctl -w kern.sysv.shmall <para> In OS X 10.3.9 and later, instead of editing <filename>/etc/rc</> - you may create a file named <filename>/etc/sysctl.conf</>, + you can create a file named <filename>/etc/sysctl.conf</>, containing variable assignments such as <programlisting> kern.sysv.shmmax=4194304 @@ -970,11 +970,11 @@ kern.sysv.shmall=1024 sort of configuration commonly used for other databases such as <application>DB/2</application>.</para> - <para> It may, however, be necessary to modify the global + <para> It might , however, be necessary to modify the global <command>ulimit</command> information in <filename>/etc/security/limits</filename>, as the default hard limits for file sizes (<varname>fsize</varname>) and numbers of - files (<varname>nofiles</varname>) may be too low. + files (<varname>nofiles</varname>) might be too low. </para> </listitem> </varlistentry> @@ -1158,7 +1158,7 @@ default:\ <quote>socially friendly</quote> values that allow many users to coexist on a machine without using an inappropriate fraction of the system resources. If you run many servers on a machine this - is perhaps what you want, but on dedicated servers you may want to + is perhaps what you want, but on dedicated servers you might want to raise this limit. </para> @@ -1179,7 +1179,7 @@ default:\ <para> In Linux 2.4 and later, the default virtual memory behavior is not optimal for <productname>PostgreSQL</productname>. Because of the - way that the kernel implements memory overcommit, the kernel may + way that the kernel implements memory overcommit, the kernel might terminate the <productname>PostgreSQL</productname> server (the master server process) if the memory demands of another process cause the system to run out of virtual memory. @@ -1214,7 +1214,7 @@ Out of Memory: Killed process 12345 (postgres). sysctl -w vm.overcommit_memory=2 </programlisting> or placing an equivalent entry in <filename>/etc/sysctl.conf</>. - You may also wish to modify the related setting + You might also wish to modify the related setting <literal>vm.overcommit_ratio</>. For details see the kernel documentation file <filename>Documentation/vm/overcommit-accounting</>. </para> @@ -1314,7 +1314,7 @@ $ <userinput>kill -INT `head -1 /usr/local/pgsql/data/postmaster.pid`</userinput <para> It is best not to use <systemitem>SIGKILL</systemitem> to shut down the server. Doing so will prevent the server from releasing - shared memory and semaphores, which may then have to be done + shared memory and semaphores, which might then have to be done manually before a new server can be started. Furthermore, <systemitem>SIGKILL</systemitem> kills the <command>postgres</command> process without letting it relay the signal to its subprocesses, diff --git a/doc/src/sgml/sources.sgml b/doc/src/sgml/sources.sgml index 1c8d25e447..e225deb138 100644 --- a/doc/src/sgml/sources.sgml +++ b/doc/src/sgml/sources.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/sources.sgml,v 2.20 2006/10/23 18:10:32 petere Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/sources.sgml,v 2.21 2007/01/31 20:56:19 momjian Exp $ --> <chapter id="source"> <title>PostgreSQL Coding Conventions</title> @@ -95,7 +95,7 @@ ereport(ERROR, func_signature_string(funcname, nargs, actual_arg_types)), errhint("Unable to choose a best candidate function. " - "You may need to add explicit typecasts."))); + "You might need to add explicit typecasts."))); </programlisting> This illustrates the use of format codes to embed run-time values into a message text. Also, an optional <quote>hint</> message is provided. @@ -276,7 +276,7 @@ Hint: the addendum <para> Rationale: keeping the primary message short helps keep it to the point, and lets clients lay out screen space on the assumption that one line is - enough for error messages. Detail and hint messages may be relegated to a + enough for error messages. Detail and hint messages can be relegated to a verbose mode, or perhaps a pop-up error-details window. Also, details and hints would normally be suppressed from the server log to save space. Reference to implementation details is best avoided since users @@ -291,7 +291,7 @@ Hint: the addendum <para> Don't put any specific assumptions about formatting into the message texts. Expect clients and the server log to wrap lines to fit their own - needs. In long messages, newline characters (\n) may be used to indicate + needs. In long messages, newline characters (\n) can be used to indicate suggested paragraph breaks. Don't end a message with a newline. Don't use tabs or other formatting characters. (In error context displays, newlines are automatically added to separate levels of context such as @@ -376,7 +376,7 @@ Hint: the addendum messages are not grammatically complete sentences anyway. (And if they're long enough to be more than one sentence, they should be split into primary and detail parts.) However, detail and hint messages are longer - and may need to include multiple sentences. For consistency, they should + and might need to include multiple sentences. For consistency, they should follow complete-sentence style even when there's only one sentence. </para> @@ -435,7 +435,7 @@ cannot open file "%s" The first one means that the attempt to open the file failed. The message should give a reason, such as <quote>disk full</quote> or <quote>file doesn't exist</quote>. The past tense is appropriate because - next time the disk might not be full anymore or the file in question may + next time the disk might not be full anymore or the file in question might exist. </para> diff --git a/doc/src/sgml/spi.sgml b/doc/src/sgml/spi.sgml index c6bf079141..0fa4bede24 100644 --- a/doc/src/sgml/spi.sgml +++ b/doc/src/sgml/spi.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/spi.sgml,v 1.49 2006/10/23 18:10:32 petere Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/spi.sgml,v 1.50 2007/01/31 20:56:19 momjian Exp $ --> <chapter id="spi"> <title>Server Programming Interface</title> @@ -38,7 +38,7 @@ Note that if a command invoked via SPI fails, then control will not be returned to your procedure. Rather, the transaction or subtransaction in which your procedure executes will be - rolled back. (This may seem surprising given that the SPI functions mostly + rolled back. (This might seem surprising given that the SPI functions mostly have documented error-return conventions. Those conventions only apply for errors detected within the SPI functions themselves, however.) It is possible to recover control after an error by establishing your own @@ -87,7 +87,7 @@ int SPI_connect(void) <function>SPI_connect</function> opens a connection from a procedure invocation to the SPI manager. You must call this function if you want to execute commands through SPI. Some utility - SPI functions may be called from unconnected procedures. + SPI functions can be called from unconnected procedures. </para> <para> @@ -305,7 +305,7 @@ int SPI_execute(const char * <parameter>command</parameter>, bool <parameter>rea </para> <para> - This function may only be called from a connected procedure. + This function can only be called from a connected procedure. </para> <para> @@ -321,7 +321,7 @@ SPI_execute("INSERT INTO foo SELECT * FROM bar", false, 5); </para> <para> - You may pass multiple commands in one string. + You can pass multiple commands in one string. <function>SPI_execute</function> returns the result for the command executed last. The <parameter>count</parameter> limit applies to each command separately, but it is not applied to @@ -366,7 +366,7 @@ SPI_execute("INSERT INTO foo SELECT * FROM bar", false, 5); <symbol>SPI_OK_INSERT_RETURNING</symbol>, <symbol>SPI_OK_DELETE_RETURNING</symbol>, or <symbol>SPI_OK_UPDATE_RETURNING</symbol>, - then you may use the + then you can use the global pointer <literal>SPITupleTable *SPI_tuptable</literal> to access the result rows. Some utility commands (such as <command>EXPLAIN</>) also return row sets, and <literal>SPI_tuptable</> @@ -388,7 +388,7 @@ typedef struct </programlisting> <structfield>vals</> is an array of pointers to rows. (The number of valid entries is given by <varname>SPI_processed</varname>.) - <structfield>tupdesc</> is a row descriptor which you may pass to + <structfield>tupdesc</> is a row descriptor which you can pass to SPI functions dealing with rows. <structfield>tuptabcxt</>, <structfield>alloced</>, and <structfield>free</> are internal fields not intended for use by SPI callers. @@ -713,7 +713,7 @@ void * SPI_prepare(const char * <parameter>command</parameter>, int <parameter>n <para> When the same or a similar command is to be executed repeatedly, it - may be advantageous to perform the planning only once. + might be advantageous to perform the planning only once. <function>SPI_prepare</function> converts a command string into an execution plan that can be executed repeatedly using <function>SPI_execute_plan</function>. @@ -792,7 +792,7 @@ void * SPI_prepare(const char * <parameter>command</parameter>, int <parameter>n <para> There is a disadvantage to using parameters: since the planner does not know the values that will be supplied for the parameters, it - may make worse planning choices than it would make for a normal + might make worse planning choices than it would make for a normal command with all constants visible. </para> </refsect1> @@ -1685,7 +1685,7 @@ void * SPI_saveplan(void * <parameter>plan</parameter>) </para> <para> - All functions described in this section may be used by both + All functions described in this section can be used by both connected and unconnected procedures. </para> @@ -2311,7 +2311,7 @@ char * SPI_getnspname(Relation <parameter>rel</parameter>) </para> <para> - All functions described in this section may be used by both + All functions described in this section can be used by both connected and unconnected procedures. In an unconnected procedure, they act the same as the underlying ordinary server functions (<function>palloc</>, etc.). diff --git a/doc/src/sgml/sql.sgml b/doc/src/sgml/sql.sgml index 3e3c32b89f..238e8b3005 100644 --- a/doc/src/sgml/sql.sgml +++ b/doc/src/sgml/sql.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/sql.sgml,v 1.43 2007/01/09 02:14:10 tgl Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/sql.sgml,v 1.44 2007/01/31 20:56:19 momjian Exp $ --> <chapter id="sql-intro"> <title>SQL</title> @@ -173,9 +173,9 @@ PART: 4 | 3 </para> <para> - The tables PART and SUPPLIER may be regarded as + The tables PART and SUPPLIER can be regarded as <firstterm>entities</firstterm> and - SELLS may be regarded as a <firstterm>relationship</firstterm> + SELLS can be regarded as a <firstterm>relationship</firstterm> between a particular part and a particular supplier. </para> @@ -949,7 +949,7 @@ SELECT PNAME, PRICE </para> <para> - Arithmetic operations may be used in the target list and in the WHERE + Arithmetic operations can be used in the target list and in the WHERE clause. For example if we want to know how much it would cost if we take two pieces of a part we could use the following query: @@ -1059,7 +1059,7 @@ select sname, pname from supplier A joined table, created using JOIN syntax, is a table reference list item that occurs in a FROM clause and before any WHERE, GROUP BY, or HAVING clause. Other table references, including table names or - other JOIN clauses, may be included in the FROM clause if separated + other JOIN clauses, can be included in the FROM clause if separated by commas. JOINed tables are logically like any other table listed in the FROM clause. </para> @@ -1239,7 +1239,7 @@ select sname, pname from supplier <para> JOINs of all types can be chained together or nested where either or both of <replaceable class="parameter">T1</replaceable> and - <replaceable class="parameter">T2</replaceable> may be JOINed tables. + <replaceable class="parameter">T2</replaceable> can be JOINed tables. Parenthesis can be used around JOIN clauses to control the order of JOINs which are otherwise processed left to right. </para> @@ -1405,7 +1405,7 @@ SELECT S.SNO, S.SNAME, COUNT(SE.PNO) <para> Note that for a query using GROUP BY and aggregate functions to make sense, the target list can only refer directly to - the attributes being grouped by. Other attributes may only be used + the attributes being grouped by. Other attributes can only be used inside the arguments of aggregate functions. Otherwise there would not be a unique value to associate with the other attributes. </para> @@ -1825,7 +1825,7 @@ CREATE INDEX I ON SUPPLIER (SNAME); <title>Create View</title> <para> - A view may be regarded as a <firstterm>virtual table</firstterm>, + A view can be regarded as a <firstterm>virtual table</firstterm>, i.e. a table that does not <emphasis>physically</emphasis> exist in the database but looks to the user diff --git a/doc/src/sgml/start.sgml b/doc/src/sgml/start.sgml index 0b4d8cf0cf..360082ff94 100644 --- a/doc/src/sgml/start.sgml +++ b/doc/src/sgml/start.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/start.sgml,v 1.43 2006/10/21 23:12:57 tgl Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/start.sgml,v 1.44 2007/01/31 20:56:19 momjian Exp $ --> <chapter id="tutorial-start"> <title>Getting Started</title> @@ -38,11 +38,11 @@ <para> If your site administrator has not set things up in the default - way, you may have some more work to do. For example, if the + way, you might have some more work to do. For example, if the database server machine is a remote machine, you will need to set the <envar>PGHOST</envar> environment variable to the name of the database server machine. The environment variable - <envar>PGPORT</envar> may also have to be set. The bottom line is + <envar>PGPORT</envar> might also have to be set. The bottom line is this: if you try to start an application program and it complains that it cannot connect to the database, you should consult your site administrator or, if that is you, the documentation to make @@ -272,7 +272,7 @@ createdb: database creation failed: ERROR: permission denied to create database </para> <para> - More about <command>createdb</command> and <command>dropdb</command> may + More about <command>createdb</command> and <command>dropdb</command> can be found in <xref linkend="APP-CREATEDB"> and <xref linkend="APP-DROPDB"> respectively. </para> diff --git a/doc/src/sgml/storage.sgml b/doc/src/sgml/storage.sgml index 3635370ca3..c20b2ebfe1 100644 --- a/doc/src/sgml/storage.sgml +++ b/doc/src/sgml/storage.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/storage.sgml,v 1.13 2006/11/25 22:55:59 petere Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/storage.sgml,v 1.14 2007/01/31 20:56:19 momjian Exp $ --> <chapter id="storage"> @@ -365,7 +365,7 @@ fixed size (usually 8 kB, although a different page size can be selected when compiling the server). In a table, all the pages are logically equivalent, so a particular item (row) can be stored in any page. In indexes, the first page is generally reserved as a <firstterm>metapage</> -holding control information, and there may be different types of pages +holding control information, and there can be different types of pages within the index, depending on the index access method. </para> @@ -503,7 +503,7 @@ data. Empty in ordinary tables.</entry> </table> <para> - All the details may be found in + All the details can be found in <filename>src/include/storage/bufpage.h</filename>. </para> @@ -519,7 +519,7 @@ data. Empty in ordinary tables.</entry> The number of item identifiers present can be determined by looking at <structfield>pd_lower</>, which is increased to allocate a new identifier. Because an item - identifier is never moved until it is freed, its index may be used on a + identifier is never moved until it is freed, its index can be used on a long-term basis to reference an item, even when the item itself is moved around on the page to compact free space. In fact, every pointer to an item (<type>ItemPointer</type>, also known as @@ -540,8 +540,8 @@ data. Empty in ordinary tables.</entry> <para> - The final section is the <quote>special section</quote> which may - contain anything the access method wishes to store. For example, + The final section is the <quote>special section</quote> which can + contain anything the access method wishes to store. For example, b-tree indexes store links to the page's left and right siblings, as well as some other data relevant to the index structure. Ordinary tables do not use a special section at all (indicated by setting @@ -647,7 +647,7 @@ data. Empty in ordinary tables.</entry> </table> <para> - All the details may be found in + All the details can be found in <filename>src/include/access/htup.h</filename>. </para> @@ -673,7 +673,7 @@ data. Empty in ordinary tables.</entry> variable length field (attlen = -1) then it's a bit more complicated. All variable-length datatypes share the common header structure <type>varattrib</type>, which includes the total length of the stored - value and some flag bits. Depending on the flags, the data may be either + value and some flag bits. Depending on the flags, the data can be either inline or in a <acronym>TOAST</> table; it might be compressed, too (see <xref linkend="storage-toast">). diff --git a/doc/src/sgml/syntax.sgml b/doc/src/sgml/syntax.sgml index 65c29b835c..9e086a58a7 100644 --- a/doc/src/sgml/syntax.sgml +++ b/doc/src/sgml/syntax.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/syntax.sgml,v 1.111 2006/10/22 03:03:41 tgl Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/syntax.sgml,v 1.112 2007/01/31 20:56:19 momjian Exp $ --> <chapter id="sql-syntax"> <title>SQL Syntax</title> @@ -120,7 +120,7 @@ INSERT INTO MY_TABLE VALUES (3, 'hi there'); key word can be letters, underscores, digits (<literal>0</literal>-<literal>9</literal>), or dollar signs (<literal>$</>). Note that dollar signs are not allowed in identifiers - according to the letter of the SQL standard, so their use may render + according to the letter of the SQL standard, so their use might render applications less portable. The SQL standard will not define a key word that contains digits or starts or ends with an underscore, so identifiers of this @@ -466,7 +466,7 @@ $function$ digits (0 through 9). At least one digit must be before or after the decimal point, if one is used. At least one digit must follow the exponent marker (<literal>e</literal>), if one is present. - There may not be any spaces or other characters embedded in the + There cannot be any spaces or other characters embedded in the constant. Note that any leading plus or minus sign is not actually considered part of the constant; it is an operator applied to the constant. @@ -537,7 +537,7 @@ CAST ( '<replaceable>string</replaceable>' AS <replaceable>type</replaceable> ) The string constant's text is passed to the input conversion routine for the type called <replaceable>type</replaceable>. The result is a constant of the indicated type. The explicit type - cast may be omitted if there is no ambiguity as to the type the + cast can be omitted if there is no ambiguity as to the type the constant must be (for example, when it is assigned directly to a table column), in which case it is automatically coerced. </para> @@ -553,7 +553,7 @@ CAST ( '<replaceable>string</replaceable>' AS <replaceable>type</replaceable> ) <synopsis> <replaceable>typename</replaceable> ( '<replaceable>string</replaceable>' ) </synopsis> - but not all type names may be used in this way; see <xref + but not all type names can be used in this way; see <xref linkend="sql-syntax-type-casts"> for details. </para> @@ -650,7 +650,7 @@ CAST ( '<replaceable>string</replaceable>' AS <replaceable>type</replaceable> ) A dollar sign (<literal>$</literal>) followed by digits is used to represent a positional parameter in the body of a function definition or a prepared statement. In other contexts the - dollar sign may be part of an identifier or a dollar-quoted string + dollar sign can be part of an identifier or a dollar-quoted string constant. </para> </listitem> @@ -743,7 +743,7 @@ CAST ( '<replaceable>string</replaceable>' AS <replaceable>type</replaceable> ) where the comment begins with <literal>/*</literal> and extends to the matching occurrence of <literal>*/</literal>. These block comments nest, as specified in the SQL standard but unlike C, so that one can - comment out larger blocks of code that may contain existing block + comment out larger blocks of code that might contain existing block comments. </para> @@ -766,7 +766,7 @@ CAST ( '<replaceable>string</replaceable>' AS <replaceable>type</replaceable> ) associativity of the operators in <productname>PostgreSQL</>. Most operators have the same precedence and are left-associative. The precedence and associativity of the operators is hard-wired - into the parser. This may lead to non-intuitive behavior; for + into the parser. This can lead to non-intuitive behavior; for example the Boolean operators <literal><</> and <literal>></> have a different precedence than the Boolean operators <literal><=</> and <literal>>=</>. Also, you will @@ -1101,7 +1101,7 @@ SELECT 3 OPERATOR(pg_catalog.+) 4; the key words <literal>NEW</literal> or <literal>OLD</literal>. (<literal>NEW</literal> and <literal>OLD</literal> can only appear in rewrite rules, while other correlation names can be used in any SQL statement.) - The correlation name and separating dot may be omitted if the column name + The correlation name and separating dot can be omitted if the column name is unique across all the tables being used in the current query. (See also <xref linkend="queries">.) </para> </sect2> @@ -1171,7 +1171,7 @@ CREATE FUNCTION dept(text) RETURNS dept <para> In general the array <replaceable>expression</replaceable> must be - parenthesized, but the parentheses may be omitted when the expression + parenthesized, but the parentheses can be omitted when the expression to be subscripted is just a column reference or positional parameter. Also, multiple subscripts can be concatenated when the original array is multidimensional. @@ -1206,7 +1206,7 @@ $1[10:42] <para> In general the row <replaceable>expression</replaceable> must be - parenthesized, but the parentheses may be omitted when the expression + parenthesized, but the parentheses can be omitted when the expression to be selected from is just a table reference or positional parameter. For example, @@ -1277,7 +1277,7 @@ sqrt(2) <para> The list of built-in functions is in <xref linkend="functions">. - Other functions may be added by the user. + Other functions can be added by the user. </para> </sect2> @@ -1334,12 +1334,12 @@ sqrt(2) <para> The predefined aggregate functions are described in <xref - linkend="functions-aggregate">. Other aggregate functions may be added + linkend="functions-aggregate">. Other aggregate functions can be added by the user. </para> <para> - An aggregate expression may only appear in the result list or + An aggregate expression can only appear in the result list or <literal>HAVING</> clause of a <command>SELECT</> command. It is forbidden in other clauses, such as <literal>WHERE</>, because those clauses are logically evaluated before the results @@ -1407,7 +1407,7 @@ CAST ( <replaceable>expression</replaceable> AS <replaceable>type</replaceable> </para> <para> - An explicit type cast may usually be omitted if there is no ambiguity as + An explicit type cast can usually be omitted if there is no ambiguity as to the type that a value expression must produce (for example, when it is assigned to a table column); the system will automatically apply a type cast in such cases. However, automatic casting is only done for @@ -1510,7 +1510,7 @@ SELECT ARRAY[1,2,3+4]; <para> Multidimensional array values can be built by nesting array constructors. - In the inner constructors, the key word <literal>ARRAY</literal> may + In the inner constructors, the key word <literal>ARRAY</literal> can be omitted. For example, these produce the same result: <programlisting> @@ -1634,7 +1634,7 @@ SELECT ROW(t.f1, t.f2, 42) FROM t; By default, the value created by a <literal>ROW</> expression is of an anonymous record type. If necessary, it can be cast to a named composite type — either the row type of a table, or a composite type - created with <command>CREATE TYPE AS</>. An explicit cast may be needed + created with <command>CREATE TYPE AS</>. An explicit cast might be needed to avoid ambiguity. For example: <programlisting> CREATE TABLE mytable(f1 int, f2 float, f3 text); @@ -1725,13 +1725,13 @@ SELECT somefunc() OR true; rely on side effects or evaluation order in <literal>WHERE</> and <literal>HAVING</> clauses, since those clauses are extensively reprocessed as part of developing an execution plan. Boolean - expressions (<literal>AND</>/<literal>OR</>/<literal>NOT</> combinations) in those clauses may be reorganized + expressions (<literal>AND</>/<literal>OR</>/<literal>NOT</> combinations) in those clauses can be reorganized in any manner allowed by the laws of Boolean algebra. </para> <para> When it is essential to force evaluation order, a <literal>CASE</> - construct (see <xref linkend="functions-conditional">) may be + construct (see <xref linkend="functions-conditional">) can be used. For example, this is an untrustworthy way of trying to avoid division by zero in a <literal>WHERE</> clause: <programlisting> diff --git a/doc/src/sgml/trigger.sgml b/doc/src/sgml/trigger.sgml index 84ca327c4f..f8e039c489 100644 --- a/doc/src/sgml/trigger.sgml +++ b/doc/src/sgml/trigger.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/trigger.sgml,v 1.47 2006/09/16 00:30:16 momjian Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/trigger.sgml,v 1.48 2007/01/31 20:56:19 momjian Exp $ --> <chapter id="triggers"> <title>Triggers</title> @@ -122,7 +122,7 @@ <para> The return value is ignored for row-level triggers fired after an - operation, and so they may as well return <symbol>NULL</>. + operation, and so they can return <symbol>NULL</>. </para> <para> @@ -152,7 +152,7 @@ <para> If a trigger function executes SQL commands then these - commands may fire triggers again. This is known as cascading + commands might fire triggers again. This is known as cascading triggers. There is no direct limitation on the number of cascade levels. It is possible for cascades to cause a recursive invocation of the same trigger; for example, an <command>INSERT</command> @@ -233,7 +233,7 @@ changes for rows previously processed in the same outer command. This requires caution, since the ordering of these change events is not in general predictable; a SQL command that - affects multiple rows may visit the rows in any order. + affects multiple rows can visit the rows in any order. </para> </listitem> @@ -332,7 +332,7 @@ typedef struct TriggerData <term><structfield>tg_event</></term> <listitem> <para> - Describes the event for which the function is called. You may use the + Describes the event for which the function is called. You can use the following macros to examine <literal>tg_event</literal>: <variablelist> @@ -524,7 +524,7 @@ typedef struct Trigger <para> Here is a very simple example of a trigger function written in C. - (Examples of triggers written in procedural languages may be found + (Examples of triggers written in procedural languages can be found in the documentation of the procedural languages.) </para> diff --git a/doc/src/sgml/typeconv.sgml b/doc/src/sgml/typeconv.sgml index f4c521025d..fe8163a74e 100644 --- a/doc/src/sgml/typeconv.sgml +++ b/doc/src/sgml/typeconv.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/typeconv.sgml,v 1.48 2006/09/18 19:54:01 tgl Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/typeconv.sgml,v 1.49 2007/01/31 20:56:19 momjian Exp $ --> <chapter Id="typeconv"> <title>Type Conversion</title> @@ -447,7 +447,7 @@ try a similar case with <literal>~</>, we get: SELECT ~ '20' AS "negation"; ERROR: operator is not unique: ~ "unknown" -HINT: Could not choose a best candidate operator. You may need to add explicit +HINT: Could not choose a best candidate operator. You might need to add explicit type casts. </screen> This happens because the system can't decide which of the several @@ -619,7 +619,7 @@ SELECT round(CAST (4 AS numeric), 4); <para> Since numeric constants with decimal points are initially assigned the type <type>numeric</type>, the following query will require no type -conversion and may therefore be slightly more efficient: +conversion and might therefore be slightly more efficient: <screen> SELECT round(4.0, 4); </screen> diff --git a/doc/src/sgml/user-manag.sgml b/doc/src/sgml/user-manag.sgml index ec5c6e43c4..c7000bc904 100644 --- a/doc/src/sgml/user-manag.sgml +++ b/doc/src/sgml/user-manag.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/user-manag.sgml,v 1.37 2006/09/05 21:08:34 tgl Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/user-manag.sgml,v 1.38 2007/01/31 20:56:19 momjian Exp $ --> <chapter id="user-manag"> <title>Database Roles and Privileges</title> @@ -126,7 +126,7 @@ SELECT rolname FROM pg_roles; </para> <para> - The set of database roles a given client connection may connect as + The set of database roles a given client connection can connect as is determined by the client authentication setup, as explained in <xref linkend="client-authentication">. (Thus, a client is not necessarily limited to connect as the role with the same name as @@ -142,7 +142,7 @@ SELECT rolname FROM pg_roles; <title>Role Attributes</title> <para> - A database role may have a number of attributes that define its + A database role can have a number of attributes that define its privileges and interact with the client authentication system. <variablelist> @@ -482,7 +482,7 @@ DROP ROLE <replaceable>name</replaceable>; <para> Functions and triggers allow users to insert code into the backend - server that other users may execute unintentionally. Hence, both + server that other users might execute unintentionally. Hence, both mechanisms permit users to <quote>Trojan horse</quote> others with relative ease. The only real protection is tight control over who can define functions. diff --git a/doc/src/sgml/wal.sgml b/doc/src/sgml/wal.sgml index 99e505db90..cf0c3d2e91 100644 --- a/doc/src/sgml/wal.sgml +++ b/doc/src/sgml/wal.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/wal.sgml,v 1.42 2006/11/25 22:44:48 petere Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/wal.sgml,v 1.43 2007/01/31 20:56:19 momjian Exp $ --> <chapter id="wal"> <title>Reliability and the Write-Ahead Log</title> @@ -40,7 +40,7 @@ </para> <para> - Next, there may be a cache in the disk drive controller; this is + Next, there might be a cache in the disk drive controller; this is particularly common on <acronym>RAID</> controller cards. Some of these caches are <firstterm>write-through</>, meaning writes are passed along to the drive as soon as they arrive. Others are @@ -106,7 +106,7 @@ <para> <firstterm>Write-Ahead Logging</firstterm> (<acronym>WAL</acronym>) is a standard approach to transaction logging. Its detailed - description may be found in most (if not all) books about + description can be found in most (if not all) books about transaction processing. Briefly, <acronym>WAL</acronym>'s central concept is that changes to data files (where tables and indexes reside) must be written only after those changes have been logged, @@ -125,7 +125,7 @@ file needs to be flushed to disk at the time of transaction commit, rather than every data file changed by the transaction. In multiuser environments, commits of many transactions - may be accomplished with a single <function>fsync</function> of + can be accomplished with a single <function>fsync</function> of the log file. Furthermore, the log file is written sequentially, and so the cost of syncing the log is much less than the cost of flushing the data pages. This is especially true for servers @@ -211,7 +211,7 @@ <varname>checkpoint_segments</varname>. Occasional appearance of such a message is not cause for alarm, but if it appears often then the checkpoint control parameters should be increased. Bulk operations such - as large <command>COPY</> transfers may cause a number of such warnings + as large <command>COPY</> transfers might cause a number of such warnings to appear if you have not set <varname>checkpoint_segments</> high enough. </para> @@ -241,13 +241,13 @@ is used on every database low level modification (for example, row insertion) at a time when an exclusive lock is held on affected data pages, so the operation needs to be as fast as possible. What - is worse, writing <acronym>WAL</acronym> buffers may also force the + is worse, writing <acronym>WAL</acronym> buffers might also force the creation of a new log segment, which takes even more time. Normally, <acronym>WAL</acronym> buffers should be written and flushed by a <function>LogFlush</function> request, which is made, for the most part, at transaction commit time to ensure that transaction records are flushed to permanent storage. On systems - with high log output, <function>LogFlush</function> requests may + with high log output, <function>LogFlush</function> requests might not occur often enough to prevent <function>LogInsert</function> from having to do writes. On such systems one should increase the number of <acronym>WAL</acronym> buffers by @@ -294,7 +294,7 @@ compiled with support for it) will result in each <function>LogInsert</function> and <function>LogFlush</function> <acronym>WAL</acronym> call being logged to the server log. This - option may be replaced by a more general mechanism in the future. + option might be replaced by a more general mechanism in the future. </para> </sect1> @@ -324,7 +324,7 @@ <para> It is of advantage if the log is located on another disk than the - main database files. This may be achieved by moving the directory + main database files. This can be achieved by moving the directory <filename>pg_xlog</filename> to another location (while the server is shut down, of course) and creating a symbolic link from the original location in the main data directory to the new location. @@ -332,11 +332,11 @@ <para> The aim of <acronym>WAL</acronym>, to ensure that the log is - written before database records are altered, may be subverted by + written before database records are altered, can be subverted by disk drives<indexterm><primary>disk drive</></> that falsely report a successful write to the kernel, when in fact they have only cached the data and not yet stored it - on the disk. A power failure in such a situation may still lead to + on the disk. A power failure in such a situation might still lead to irrecoverable data corruption. Administrators should try to ensure that disks holding <productname>PostgreSQL</productname>'s <acronym>WAL</acronym> log files do not make such false reports. diff --git a/doc/src/sgml/xaggr.sgml b/doc/src/sgml/xaggr.sgml index 20664535cb..3013392646 100644 --- a/doc/src/sgml/xaggr.sgml +++ b/doc/src/sgml/xaggr.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/xaggr.sgml,v 1.33 2006/09/16 00:30:16 momjian Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/xaggr.sgml,v 1.34 2007/01/31 20:56:20 momjian Exp $ --> <sect1 id="xaggr"> <title>User-Defined Aggregates</title> @@ -28,7 +28,7 @@ <para> Thus, in addition to the argument and result data types seen by a user of the aggregate, there is an internal state-value data type that - may be different from both the argument and result types. + might be different from both the argument and result types. </para> <para> @@ -112,12 +112,12 @@ CREATE AGGREGATE avg (float8) </para> <para> - Aggregate functions may use polymorphic + Aggregate functions can use polymorphic state transition functions or final functions, so that the same functions can be used to implement multiple aggregates. See <xref linkend="extend-types-polymorphic"> for an explanation of polymorphic functions. - Going a step further, the aggregate function itself may be specified + Going a step further, the aggregate function itself can be specified with polymorphic input type(s) and state type, allowing a single aggregate definition to serve for multiple input data types. Here is an example of a polymorphic aggregate: diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index ca9d4261ff..d45f909206 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/xfunc.sgml,v 1.122 2007/01/30 22:29:23 momjian Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/xfunc.sgml,v 1.123 2007/01/31 20:56:20 momjian Exp $ --> <sect1 id="xfunc"> <title>User-Defined Functions</title> @@ -44,7 +44,7 @@ of function can take base types, composite types, or combinations of these as arguments (parameters). In addition, every kind of function can return a base type or - a composite type. Functions may also be defined to return + a composite type. Functions can also be defined to return sets of base or composite values. </para> @@ -95,7 +95,7 @@ <para> <indexterm><primary>SETOF</><seealso>function</></> Alternatively, - an SQL function may be declared to return a set, by specifying the + an SQL function can be declared to return a set, by specifying the function's return type as <literal>SETOF <replaceable>sometype</></literal>. In this case all rows of the last query's result are returned. Further details appear below. @@ -157,7 +157,7 @@ SELECT clean_emp(); body using the syntax <literal>$<replaceable>n</></>: <literal>$1</> refers to the first argument, <literal>$2</> to the second, and so on. If an argument is of a composite type, then the dot notation, - e.g., <literal>$1.name</literal>, may be used to access attributes + e.g., <literal>$1.name</literal>, can be used to access attributes of the argument. The arguments can only be used as data values, not as identifiers. Thus for example this is reasonable: <programlisting> @@ -588,7 +588,7 @@ DROP FUNCTION sum_n_product (int, int); <title><acronym>SQL</acronym> Functions as Table Sources</title> <para> - All SQL functions may be used in the <literal>FROM</> clause of a query, + All SQL functions can be used in the <literal>FROM</> clause of a query, but it is particularly useful for functions returning composite types. If the function is defined to return a base type, the table function produces a one-column table. If the function is defined to return @@ -662,11 +662,11 @@ SELECT * FROM getfoo(1) AS t1; </para> <para> - Currently, functions returning sets may also be called in the select list + Currently, functions returning sets can also be called in the select list of a query. For each row that the query generates by itself, the function returning set is invoked, and an output row is generated for each element of the function's result set. Note, - however, that this capability is deprecated and may be removed in future + however, that this capability is deprecated and might be removed in future releases. The following is an example function returning a set from the select list: @@ -716,7 +716,7 @@ SELECT name, listchildren(name) FROM nodes; <title>Polymorphic <acronym>SQL</acronym> Functions</title> <para> - <acronym>SQL</acronym> functions may be declared to accept and + <acronym>SQL</acronym> functions can be declared to accept and return the polymorphic types <type>anyelement</type> and <type>anyarray</type>. See <xref linkend="extend-types-polymorphic"> for a more detailed @@ -799,7 +799,7 @@ SELECT * FROM dup(22); </indexterm> <para> - More than one function may be defined with the same SQL name, so long + More than one function can be defined with the same SQL name, so long as the arguments they take are different. In other words, function names can be <firstterm>overloaded</firstterm>. When a query is executed, the server will determine which function to @@ -941,7 +941,7 @@ CREATE FUNCTION test(int, int) RETURNS int a lot whether a function is executed once during planning or once during query execution startup. But there is a big difference if the plan is saved and reused later. Labeling a function <literal>IMMUTABLE</> when - it really isn't may allow it to be prematurely folded to a constant during + it really isn't might allow it to be prematurely folded to a constant during planning, resulting in a stale value being re-used during subsequent uses of the plan. This is a hazard when using prepared statements or when using function languages that cache plans (such as @@ -1310,7 +1310,7 @@ typedef int int4; </para> <para> - On the other hand, fixed-length types of any size may + On the other hand, fixed-length types of any size can be passed by-reference. For example, here is a sample implementation of a <productname>PostgreSQL</productname> type: @@ -1347,7 +1347,7 @@ typedef struct <para> <emphasis>Never</> modify the contents of a pass-by-reference input value. If you do so you are likely to corrupt on-disk data, since - the pointer you are given may well point directly into a disk buffer. + the pointer you are given might point directly into a disk buffer. The sole exception to this rule is explained in <xref linkend="xaggr">. </para> @@ -1402,7 +1402,7 @@ memcpy(destination->data, buffer, 40); that uses a built-in type of <productname>PostgreSQL</>. The <quote>Defined In</quote> column gives the header file that needs to be included to get the type definition. (The actual - definition may be in a different file that is included by the + definition might be in a different file that is included by the listed file. It is recommended that users stick to the defined interface.) Note that you should always include <filename>postgres.h</filename> first in any source file, because @@ -1708,7 +1708,7 @@ CREATE FUNCTION concat_text(text, text) RETURNS text (Better style would be to use just <literal>'funcs'</> in the <literal>AS</> clause, after having added <replaceable>DIRECTORY</replaceable> to the search path. In any - case, we may omit the system-specific extension for a shared + case, we can omit the system-specific extension for a shared library, commonly <literal>.so</literal> or <literal>.sl</literal>.) </para> @@ -1866,7 +1866,7 @@ concat_text(PG_FUNCTION_ARGS) </para> <para> - At first glance, the version-1 coding conventions may appear to + At first glance, the version-1 coding conventions might appear to be just pointless obscurantism. They do, however, offer a number of improvements, because the macros can hide unnecessary detail. An example is that in coding <function>add_one_float8</>, we no longer need to @@ -1938,7 +1938,7 @@ concat_text(PG_FUNCTION_ARGS) <para> Before we turn to the more advanced topics, we should discuss some coding rules for <productname>PostgreSQL</productname> - C-language functions. While it may be possible to load functions + C-language functions. While it might be possible to load functions written in languages other than C into <productname>PostgreSQL</productname>, this is usually difficult (when it is possible at all) because other languages, such as @@ -1999,8 +1999,8 @@ concat_text(PG_FUNCTION_ARGS) <function>memset</function>. Without this, it's difficult to support hash indexes or hash joins, as you must pick out only the significant bits of your data structure to compute a hash. - Even if you initialize all fields of your structure, there may be - alignment padding (holes in the structure) that may contain + Even if you initialize all fields of your structure, there might be + alignment padding (holes in the structure) that contain garbage values. </para> </listitem> @@ -2265,9 +2265,9 @@ include $(PGXS) <para> Composite types do not have a fixed layout like C structures. - Instances of a composite type may contain null fields. In + Instances of a composite type can contain null fields. In addition, composite types that are part of an inheritance - hierarchy may have different fields than other members of the + hierarchy can have different fields than other members of the same inheritance hierarchy. Therefore, <productname>PostgreSQL</productname> provides a function interface for accessing fields of composite types from C. @@ -2829,7 +2829,7 @@ CREATE OR REPLACE FUNCTION retcomposite(IN integer, IN integer, <title>Polymorphic Arguments and Return Types</title> <para> - C-language functions may be declared to accept and + C-language functions can be declared to accept and return the polymorphic types <type>anyelement</type> and <type>anyarray</type>. See <xref linkend="extend-types-polymorphic"> for a more detailed explanation @@ -2913,7 +2913,7 @@ CREATE FUNCTION make_array(anyelement) RETURNS anyarray <title>Shared Memory and LWLocks</title> <para> - Add-ins may reserve LWLocks and an allocation of shared memory on server + Add-ins can reserve LWLocks and an allocation of shared memory on server startup. The add-in's shared library must be preloaded by specifying it in <xref linkend="guc-shared-preload-libraries"><indexterm><primary>shared-preload-libraries</></>. diff --git a/doc/src/sgml/xindex.sgml b/doc/src/sgml/xindex.sgml index 79610c30ed..e01d380942 100644 --- a/doc/src/sgml/xindex.sgml +++ b/doc/src/sgml/xindex.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/xindex.sgml,v 1.56 2007/01/23 20:45:28 tgl Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/xindex.sgml,v 1.57 2007/01/31 20:56:20 momjian Exp $ --> <sect1 id="xindex"> <title>Interfacing Extensions To Indexes</title> @@ -49,7 +49,7 @@ called because one thing they specify is the set of <literal>WHERE</>-clause operators that can be used with an index (i.e., can be converted into an index-scan qualification). An - operator class may also specify some <firstterm>support + operator class can also specify some <firstterm>support procedures</> that are needed by the internal operations of the index method, but do not directly correspond to any <literal>WHERE</>-clause operator that can be used with the index. @@ -663,7 +663,7 @@ CREATE OPERATOR CLASS complex_abs_ops To handle these needs, <productname>PostgreSQL</productname> uses the concept of an <firstterm>operator family</><indexterm><primary>operator family</></indexterm>. - An operator family contains one or more operator classes, and may also + An operator family contains one or more operator classes, and can also contain indexable operators and corresponding support functions that belong to the family as a whole but not to any single class within the family. We say that such operators and functions are <quote>loose</> @@ -923,7 +923,7 @@ SELECT * FROM table WHERE integer_column < 4; Consider again the situation where we are storing in the index only the bounding box of a complex object such as a polygon. In this case there's not much value in storing the whole polygon in the index - entry — we may as well store just a simpler object of type + entry — we might as well store just a simpler object of type <type>box</>. This situation is expressed by the <literal>STORAGE</> option in <command>CREATE OPERATOR CLASS</>: we'd write something like diff --git a/doc/src/sgml/xoper.sgml b/doc/src/sgml/xoper.sgml index f639407866..e8e7c0da3f 100644 --- a/doc/src/sgml/xoper.sgml +++ b/doc/src/sgml/xoper.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/xoper.sgml,v 1.38 2007/01/20 20:45:38 tgl Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/xoper.sgml,v 1.39 2007/01/31 20:56:20 momjian Exp $ --> <sect1 id="xoper"> <title>User-Defined Operators</title> @@ -230,7 +230,7 @@ column OP constant This assists the optimizer by giving it some idea of how many rows will be eliminated by <literal>WHERE</> clauses that have this form. (What happens if the constant is on - the left, you may be wondering? Well, that's one of the things that + the left, you might be wondering? Well, that's one of the things that <literal>COMMUTATOR</> is for...) </para> @@ -280,7 +280,7 @@ column OP constant <para> There are additional selectivity estimation functions designed for geometric operators in <filename>src/backend/utils/adt/geo_selfuncs.c</filename>: <function>areasel</function>, <function>positionsel</function>, - and <function>contsel</function>. At this writing these are just stubs, but you may want + and <function>contsel</function>. At this writing these are just stubs, but you might want to use them (or even better, improve them) anyway. </para> </sect2> @@ -354,7 +354,7 @@ table1.column1 OP table2.column2 <para> Care should be exercised when preparing a hash function, because there are machine-dependent ways in which it might fail to do the right thing. - For example, if your data type is a structure in which there may be + For example, if your data type is a structure in which there might be uninteresting pad bits, you can't simply pass the whole structure to <function>hash_any</>. (Unless you write your other operators and functions to ensure that the unused bits are always zero, which is the @@ -380,7 +380,7 @@ table1.column1 OP table2.column2 strict, the function must also be complete: that is, it should return true or false, never null, for any two nonnull inputs. If this rule is - not followed, hash-optimization of <literal>IN</> operations may + not followed, hash-optimization of <literal>IN</> operations might generate wrong results. (Specifically, <literal>IN</> might return false where the correct answer according to the standard would be null; or it might yield an error complaining that it wasn't prepared for a @@ -431,7 +431,7 @@ table1.column1 OP table2.column2 A merge-joinable operator must have a commutator (itself if the two operand data types are the same, or a related equality operator if they are different) that appears in the same operator family. - If this is not the case, planner errors may occur when the operator + If this is not the case, planner errors might occur when the operator is used. Also, it is a good idea (but not strictly required) for a btree operator family that supports multiple datatypes to provide equality operators for every combination of the datatypes; this diff --git a/doc/src/sgml/xplang.sgml b/doc/src/sgml/xplang.sgml index d4b1163145..b49c406f53 100644 --- a/doc/src/sgml/xplang.sgml +++ b/doc/src/sgml/xplang.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/xplang.sgml,v 1.32 2006/11/20 17:42:16 neilc Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/xplang.sgml,v 1.33 2007/01/31 20:56:20 momjian Exp $ --> <chapter id="xplang"> <title id="xplang-title">Procedural Languages</title> @@ -57,7 +57,7 @@ only necessary to execute <command>CREATE LANGUAGE</> <replaceable>language_name</> to install the language into the current database. Alternatively, the program <xref - linkend="app-createlang"> may be used to do this from the shell + linkend="app-createlang"> can be used to do this from the shell command line. For example, to install the language <application>PL/pgSQL</application> into the database <literal>template1</>, use @@ -111,7 +111,7 @@ CREATE FUNCTION <replaceable>handler_function_name</replaceable>() <step performance="optional" id="xplang-install-cr3"> <para> - Optionally, the language handler may provide a <quote>validator</> + Optionally, the language handler can provide a <quote>validator</> function that checks a function definition for correctness without actually executing it. The validator function is called by <command>CREATE FUNCTION</> if it exists. If a validator function diff --git a/src/backend/parser/parse_func.c b/src/backend/parser/parse_func.c index f6a931f911..531d9a7af6 100644 --- a/src/backend/parser/parse_func.c +++ b/src/backend/parser/parse_func.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/parser/parse_func.c,v 1.191 2007/01/05 22:19:34 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/parser/parse_func.c,v 1.192 2007/01/31 20:56:20 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -213,7 +213,7 @@ ParseFuncOrColumn(ParseState *pstate, List *funcname, List *fargs, func_signature_string(funcname, nargs, actual_arg_types)), errhint("Could not choose a best candidate function. " - "You may need to add explicit type casts."), + "You might need to add explicit type casts."), parser_errposition(pstate, location))); else ereport(ERROR, @@ -222,7 +222,7 @@ ParseFuncOrColumn(ParseState *pstate, List *funcname, List *fargs, func_signature_string(funcname, nargs, actual_arg_types)), errhint("No function matches the given name and argument types. " - "You may need to add explicit type casts."), + "You might need to add explicit type casts."), parser_errposition(pstate, location))); } diff --git a/src/backend/parser/parse_oper.c b/src/backend/parser/parse_oper.c index 3052fd0563..1719418187 100644 --- a/src/backend/parser/parse_oper.c +++ b/src/backend/parser/parse_oper.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/parser/parse_oper.c,v 1.91 2007/01/05 22:19:34 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/parser/parse_oper.c,v 1.92 2007/01/31 20:56:20 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -771,7 +771,7 @@ op_error(ParseState *pstate, List *op, char oprkind, errmsg("operator is not unique: %s", op_signature_string(op, oprkind, arg1, arg2)), errhint("Could not choose a best candidate operator. " - "You may need to add explicit type casts."), + "You might need to add explicit type casts."), parser_errposition(pstate, location))); else ereport(ERROR, @@ -779,7 +779,7 @@ op_error(ParseState *pstate, List *op, char oprkind, errmsg("operator does not exist: %s", op_signature_string(op, oprkind, arg1, arg2)), errhint("No operator matches the given name and argument type(s). " - "You may need to add explicit type casts."), + "You might need to add explicit type casts."), parser_errposition(pstate, location))); } |