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Diffstat (limited to 'Docs/manual.texi')
| -rw-r--r-- | Docs/manual.texi | 168 |
1 files changed, 94 insertions, 74 deletions
diff --git a/Docs/manual.texi b/Docs/manual.texi index e33dfb5cfd2..79c867353c6 100644 --- a/Docs/manual.texi +++ b/Docs/manual.texi @@ -3434,6 +3434,11 @@ When using @code{SET CHARACTER SET}, one can't use translated characters in database, table, and column names. @item +If you have a @code{DECIMAL} column with a number stored in different +formats (+01.00, 1.00, 01.00), @code{GROUP BY} may regard each value +as a different value. + +@item @code{DELETE FROM merge_table} used without a @code{WHERE} will only clear the mapping for the table, not delete everything in the mapped tables. @@ -16389,6 +16394,7 @@ to restart @code{mysqld} with @code{--skip-grant-tables} to run * Privilege changes:: When Privilege Changes Take Effect * Default privileges:: Setting Up the Initial MySQL Privileges * Adding users:: Adding New Users to MySQL +* User resources:: * Passwords:: Setting Up Passwords * Password security:: Keeping Your Password Secure * Secure connections:: Using Secure Connections @@ -16417,7 +16423,8 @@ GRANT priv_type [(column_list)] [, priv_type [(column_list)] ...] [CIPHER cipher [AND]] [ISSUER issuer [AND]] [SUBJECT subject]] - [WITH [GRANT OPTION | MAX_QUERIES_PER_HOUR=#]] + [WITH [GRANT OPTION | MAX_QUERIES_PER_HOUR=# | MAX_UPDATES_PER_HOUR=#| + MAX_CONNECTIONS_PER_HOUR=#]] REVOKE priv_type [(column_list)] [, priv_type [(column_list)] ...] ON @{tbl_name | * | *.* | db_name.*@} @@ -16580,11 +16587,11 @@ to other users any privileges the user has at the specified privilege level. You should be careful to whom you give the @strong{grant} privilege, as two users with different privileges may be able to join privileges! -@code{MAX_QUERIES_PER_HOUR=#} limits the number of queries the user can -do during one hour. If @code{#} is 0, then this means that there is no -limit of the number of queries. This works by MySQL resetting a user -specific query counter to 0, after it has gone more than one hour -since the counter started incrementing. +@code{MAX_QUERIES_PER_HOUR=#}, @code{MAX_UPDATES_PER_HOUR=#} and +@code{MAX_CONNECTIONS_PER_HOUR=#} limits the limits the number of +queries/updates and logins the user can do during one hour. +If @code{#} is 0 (default), then this means that there is no limitations +for the user. @xref{User resources}. You cannot grant another user a privilege you don't have yourself; the @strong{grant} privilege allows you to give away only those privileges @@ -16875,7 +16882,7 @@ you should copy them back from your MySQL distribution before running @code{mysql_install_db}. -@node Adding users, Passwords, Default privileges, User Account Management +@node Adding users, User resources, Default privileges, User Account Management @subsection Adding New Users to MySQL @findex GRANT statement @@ -17068,7 +17075,72 @@ You can find these utilities in the Contrib directory of the MySQL web site (@uref{http://www.mysql.com/Downloads/Contrib/}). -@node Passwords, Password security, Adding users, User Account Management +@node User resources, Passwords, Adding users, User Account Management +@subsection Limiting user resources + +Starting from MySQL 4.0.2 one can limit certain resources per user. + +Before the only available method of limiting user usage of MySQL server +resources has been setting @code{max_user_connections} startup variable +to some non-zero value at MySQL startup. But this method is strictly a +global one and does not allow management of individual users, which +could be of paricular interest to Interent Service Providers. + +Therefore, management of three resources is introduced on the +individual user level : + +@itemize @bullet +@item +Number of all queries per hour +@item +Number of all updates per hour. As updates is considered any command that +changes any table or database. +@item +Number of connections made per hour +@end itemize + +A user in the above context is single entry in user table, which is +uniquely identified by user and host columns. + +All users are by default not limited in using the above resources, +unless the limits are GRANTed to them. These limits can be granted +ONLY by global GRANT (*.*) and with a following syntax : + +@example +GRANT ... WITH MAX_QUERIES_PER_HOUR = N1 MAX_UPDATES_PER_HOUR = N2 +MAX_CONNECTIONS_PER_HOUR = N3; +@end example + +One can specify any combination of the above resources. +N1, N2 and N3 are integers and stands for count / hour. + +If user reaches any of the above limits withing one hour, his connection +will be broken or refused and the appropriate error message shall be +issued. + +Current values of particular user resources can be flushed (set to +zero) by issuing a grant statement with any of the above limiting +clauses, including a GRANT statement with current value(s) of tha +resource(s). + +Also, current values for all users will be flushed if privileges are +reloaded or if the folloing new flush command is issuedd : + +@example +FLUSH USER_RESOURCES +@end example + +Also, current values for all users will be flushed with mysqladmin +reload command. + +This new feature is enabled as soon as single user is @code{GRANT}ed with +some of the limiting @code{GRANT} clauses. + +As a prerequisite for enabling this features, user table in mysql +database must have the additional columns, just as defined in table +creation scripts @code{mysql_install_db} in the @code{scripts} directory. + +@node Passwords, Password security, User resources, User Account Management @subsection Setting Up Passwords @findex PASSWORD() @@ -19377,6 +19449,7 @@ The status variables listed above have the following meaning: @item @code{Delayed_writes} @tab Number of rows written with @code{INSERT DELAYED}. @item @code{Delayed_errors} @tab Number of rows written with @code{INSERT DELAYED} for which some error occurred (probably @code{duplicate key}). @item @code{Flush_commands} @tab Number of executed @code{FLUSH} commands. +@item @code{Handler_commit} @tab Number of internal @code{COMMIT} commands. @item @code{Handler_delete} @tab Number of times a row was deleted from a table. @item @code{Handler_read_first} @tab Number of times the first entry was read from an index. If this is high, it suggests that the server is doing a lot of full index scans, for example, @@ -19386,12 +19459,14 @@ is high, it is a good indication that your queries and tables are properly index @item @code{Handler_read_next} @tab Number of requests to read next row in key order. This will be incremented if you are querying an index column with a range constraint. This also will be incremented if you are doing an index scan. +@item @code{Handler_read_prev} @tab Number of requests to read previous row in key order. This is mainly used to optimize @code{ORDER BY ... DESC}. @item @code{Handler_read_rnd} @tab Number of requests to read a row based on a fixed position. This will be high if you are doing a lot of queries that require sorting of the result. @item @code{Handler_read_rnd_next} @tab Number of requests to read the next row in the datafile. This will be high if you are doing a lot of table scans. Generally this suggests that your tables are not properly indexed or that your queries are not written to take advantage of the indexes you have. +@item @code{Handler_rollback} @tab Number of internal @code{ROLLBACK} commands. @item @code{Handler_update} @tab Number of requests to update a row in a table. @item @code{Handler_write} @tab Number of requests to insert a row in a table. @item @code{Key_blocks_used} @tab The number of used blocks in the key cache. @@ -19406,6 +19481,7 @@ have. @item @code{Open_files} @tab Number of files that are open. @item @code{Open_streams} @tab Number of streams that are open (used mainly for logging). @item @code{Opened_tables} @tab Number of tables that have been opened. +@item @code{Rpl_status} @tab Status of failsafe replication. (Not yet in use). @item @code{Select_full_join} @tab Number of joins without keys (Should be 0). @item @code{Select_full_range_join} @tab Number of joins where we used a range search on reference table. @item @code{Select_range} @tab Number of joins where we used ranges on the first table. (It's normally not critical even if this is big.) @@ -19414,12 +19490,14 @@ have. @item @code{Questions} @tab Number of queries sent to the server. @item @code{Slave_open_temp_tables} @tab Number of temporary tables currently open by the slave thread +@item @code{Slave_running} @tab Is @code{ON} if this is a slave that is connected to a master. @item @code{Slow_launch_threads} @tab Number of threads that have taken more than @code{slow_launch_time} to connect. @item @code{Slow_queries} @tab Number of queries that have taken more than @code{long_query_time}. @xref{Slow query log}. @item @code{Sort_merge_passes} @tab Number of merges the sort has to do. If this value is large you should consider increasing @code{sort_buffer}. @item @code{Sort_range} @tab Number of sorts that where done with ranges. @item @code{Sort_rows} @tab Number of sorted rows. @item @code{Sort_scan} @tab Number of sorts that where done by scanning the table. +@item @code{ssl_xxx} @tab Variables used by SSL; Not yet implemented. @item @code{Table_locks_immediate} @tab Number of times a table lock was acquired immediately. Available after 3.23.33. @item @code{Table_locks_waited} @tab Number of times a table lock could not @@ -44293,7 +44371,7 @@ have both a normal and a thread-safe client library. To get a threaded client where you can interrupt the client from other threads and set timeouts when talking with the MySQL server, you should -use the @code{-lmysys}, @code{-lstring}, and @code{-ldbug} libraries and +use the @code{-lmysys}, @code{-lmystrings}, and @code{-ldbug} libraries and the @code{net_serv.o} code that the server uses. If you don't need interrupts or timeouts, you can just compile a @@ -49215,72 +49293,14 @@ Our TODO section contains what we plan to have in 4.0. @xref{TODO MySQL 4.0}. @itemize @bullet @item -Fixed bug in DROP DATABASE with symlink +Fixed bug in @code{DROP DATABASE} with symlink @item -Fixed bug in EXPLAIN with LIMIT offset != 0 +Fixed bug in @code{EXPLAIN} with @code{LIMIT offset != 0} @item - -New feature : - -Management of user resources - -So far, the only available method of limiting user usage of MySQL -server resources has been setting max_user_connections startup -variable to some non-zero value at MySQL startup. But this method is -strictly a global one and does not allow management of individual -users, which could be of paricular interest to Interent Service -Providers. - -Therefore, management of three resources is introduced on the -individual user level : - -* number of all queries per hour -* number of all updates per hour -* number of connections made per hour - -Small clarification : By the updates in the above sense is considered -any command that changes any table or database. Queries in the above -context comprehend all commands that could be run by user. User in the -above context comprehends a single entry in user table, which is -uniquely identified by user and host columns. - -All users are by default not limited in using the above resources, -unless the limits are GRANTed to them. These limits can be granted -ONLY by global GRANT (*.*) and with a following syntax : - -GRANT ... WITH MAX_QUERIES_PER_HOUR = N1 MAX_UPDATES_PER_HOUR = N2 -MAX_CONNECTIONS_PER_HOUR = N3; - -It is not required that all three resources are specified. One or two -can be specified also. N1,N2 and N3 are intergers and should limit -number of times user can execute any command, update command or can -login that many times per hour. - -If user reaches any of the above limits withing one hour, his -connection will be broken or refused and the appropriate error message -shall be issued. - -Current values of particular user resources can be flushed (set to -zero) by issuing a grant statement with any of the above limiting -clauses, including a GRANT statement with current value(s) of tha -resource(s). - -Also, current values for all users will be flushed if privileges are -reloaded or if a new flush command is issued : - -flush user_resources. - -Also, current values for all users will be flushed with mysqladmin -reload command. - -This new feature is enabled as soon as single user is GRANTed with -some of the limiting GRANT clauses. - -As a prerequisite for enabling this features, user table in mysql -database must have the additional columns, just as defined in table -creation scripts mysql_install_db and mysql_install_db.sh in scripts/ -directory. - +Fixed bug in @code{SELECT SQL_CALC_FOUND_ROWS DISTINCT ... LIMIT #} +@item +Added limiting of user resources like queries per hour, updates per hour +and connections made per hour. @item New configure option --without-query-cache. @item @@ -55339,7 +55359,7 @@ New math functions: The @code{configure} source now compiles a thread-free client library @code{-lmysqlclient}. This is the only library that needs to be linked with client applications. When using the binary releases, you must -link with @code{-lmysql -lmysys -ldbug -lstrings} as before. +link with @code{-lmysql -lmysys -ldbug -lmystrings} as before. @item New @code{readline} library from @code{bash-2.0}. @item |