Most error messages about a relkind that was not supported or
appropriate for the command was of the pattern
"relation \"%s\" is not a table, foreign table, or materialized view"
This style can become verbose and tedious to maintain. Moreover, it's
not very helpful: If I'm trying to create a comment on a TOAST table,
which is not supported, then the information that I could have created
a comment on a materialized view is pointless.
Instead, write the primary error message shorter and saying more
directly that what was attempted is not possible. Then, in the detail
message, explain that the operation is not supported for the relkind
the object was. To simplify that, add a new function
errdetail_relkind_not_supported() that does this.
In passing, make use of RELKIND_HAS_STORAGE() where appropriate,
instead of listing out the relkinds individually.
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://www.postgresql.org/message-id/flat/dc35a398-37d0-75ce-07ea-1dd71d98f8ec@2ndquadrant.com
TOAST tables have a visibility map and a free space map, so they can be supported by pgstattuple_approx just fine. Add test cases to show how various pgstattuple functions accept TOAST tables. Also add similar tests to pg_visibility, which already accepted TOAST tables correctly but had no test coverage for them. Reviewed-by: Laurenz Albe <laurenz.albe@cybertec.at> Discussion: https://www.postgresql.org/message-id/flat/27c4496a-02b9-dc87-8f6f-bddbef54e0fe@2ndquadrant.com
Make nbtree treat all index tuples as having a heap TID attribute. Index searches can distinguish duplicates by heap TID, since heap TID is always guaranteed to be unique. This general approach has numerous benefits for performance, and is prerequisite to teaching VACUUM to perform "retail index tuple deletion". Naively adding a new attribute to every pivot tuple has unacceptable overhead (it bloats internal pages), so suffix truncation of pivot tuples is added. This will usually truncate away the "extra" heap TID attribute from pivot tuples during a leaf page split, and may also truncate away additional user attributes. This can increase fan-out, especially in a multi-column index. Truncation can only occur at the attribute granularity, which isn't particularly effective, but works well enough for now. A future patch may add support for truncating "within" text attributes by generating truncated key values using new opclass infrastructure. Only new indexes (BTREE_VERSION 4 indexes) will have insertions that treat heap TID as a tiebreaker attribute, or will have pivot tuples undergo suffix truncation during a leaf page split (on-disk compatibility with versions 2 and 3 is preserved). Upgrades to version 4 cannot be performed on-the-fly, unlike upgrades from version 2 to version 3. contrib/amcheck continues to work with version 2 and 3 indexes, while also enforcing stricter invariants when verifying version 4 indexes. These stricter invariants are the same invariants described by "3.1.12 Sequencing" from the Lehman and Yao paper. A later patch will enhance the logic used by nbtree to pick a split point. This patch is likely to negatively impact performance without smarter choices around the precise point to split leaf pages at. Making these two mostly-distinct sets of enhancements into distinct commits seems like it might clarify their design, even though neither commit is particularly useful on its own. The maximum allowed size of new tuples is reduced by an amount equal to the space required to store an extra MAXALIGN()'d TID in a new high key during leaf page splits. The user-facing definition of the "1/3 of a page" restriction is already imprecise, and so does not need to be revised. However, there should be a compatibility note in the v12 release notes. Author: Peter Geoghegan Reviewed-By: Heikki Linnakangas, Alexander Korotkov Discussion: https://postgr.es/m/CAH2-WzkVb0Kom=R+88fDFb=JSxZMFvbHVC6Mn9LJ2n=X=kS-Uw@mail.gmail.com
Commit 8b08f7d4820f failed to update these modules to at least give non-broken error messages for partitioned indexes. Add appropriate error support to them. Peter G. was complaining about a problem of unfriendly error messages; while we haven't fixed that yet, subsequent discussion let to discovery of these unhandled cases. Author: Michaël Paquier Reported-by: Peter Geoghegan Discussion: https://postgr.es/m/CAH2-WzkOKptQiE51Bh4_xeEHhaBwHkZkGtKizrFMgEkfUuRRQg@mail.gmail.com
Fix the lone error message in the whole source tree to use capitalized HASH when referring to hash indexes, making it look like all the other messages. Someday it would be good to standardize 'B-Tree', 'B-tree', 'btree', and random other spellings, too, but that's a larger patch ... Author: Álvaro Herrera
Vacuum of index consists from two stages: multiple (zero of more) ambulkdelete calls and one amvacuumcleanup call. When workload on particular table is append-only, then autovacuum isn't intended to touch this table. However, user may run vacuum manually in order to fill visibility map and get benefits of index-only scans. Then ambulkdelete wouldn't be called for indexes of such table (because no heap tuples were deleted), only amvacuumcleanup would be called In this case, amvacuumcleanup would perform full index scan for two objectives: put recyclable pages into free space map and update index statistics. This patch allows btvacuumclanup to skip full index scan when two conditions are satisfied: no pages are going to be put into free space map and index statistics isn't stalled. In order to check first condition, we store oldest btpo_xact in the meta-page. When it's precedes RecentGlobalXmin, then there are some recyclable pages. In order to check second condition we store number of heap tuples observed during previous full index scan by cleanup. If fraction of newly inserted tuples is less than vacuum_cleanup_index_scale_factor, then statistics isn't considered to be stalled. vacuum_cleanup_index_scale_factor can be defined as both reloption and GUC (default). This patch bumps B-tree meta-page version. Upgrade of meta-page is performed "on the fly": during VACUUM meta-page is rewritten with new version. No special handling in pg_upgrade is required. Author: Masahiko Sawada, Alexander Korotkov Review by: Peter Geoghegan, Kyotaro Horiguchi, Alexander Korotkov, Yura Sokolov Discussion: https://www.postgresql.org/message-id/flat/CAD21AoAX+d2oD_nrd9O2YkpzHaFr=uQeGr9s1rKC3O4ENc568g@mail.gmail.com
Per a report from AP, it's not that hard to exhaust the supply of bitmap pages if you create a table with a hash index and then insert a few billion rows - and then you start getting errors when you try to insert additional rows. In the particular case reported by AP, there's another fix that we can make to improve recycling of overflow pages, which is another way to avoid the error, but there may be other cases where this problem happens and that fix won't help. So let's buy ourselves as much headroom as we can without rearchitecting anything. The comments claim that the old limit was 64GB, but it was really only 32GB, because we didn't use all the bits in the page for bitmap bits - only the largest power of 2 that could fit after deducting space for the page header and so forth. Thus, we have 4kB per page for bitmap bits, not 8kB. The new limit is thus actually 8 times the old *real* limit but only 4 times the old *purported* limit. Since this breaks on-disk compatibility, bump HASH_VERSION. We've already done this earlier in this release cycle, so this doesn't cause any incremental inconvenience for people using pg_upgrade from releases prior to v10. However, users who use pg_upgrade to reach 10beta3 or later from 10beta2 or earlier will need to REINDEX any hash indexes again. Amit Kapila and Robert Haas Discussion: http://postgr.es/m/20170704105728.mwb72jebfmok2nm2@zip.com.au
Hash indexes can contain both pages which are all-zeroes (i.e. PageIsNew()) and pages which have been initialized but currently aren't used. The latter category can happen either when a page has been reserved but not yet used or when it is used for a time and then freed. pgstattuple was only prepared to deal with the pages that are actually-zeroes, which it called zero_pages. Rename the column to unused_pages (extension version 1.5 is as-yet-unreleased) and make it count both kinds of unused pages. Along the way, slightly tidy up the way we test for pages of various types. Robert Haas and Ashutosh Sharma, reviewed by Amit Kapila Discussion: http://postgr.es/m/CAE9k0PkTtKFB3YndOyQMjwuHx+-FtUP1ynK8E-nHtetoow3NtQ@mail.gmail.com
Since hash indexes typically have very few overflow pages, adding a new splitpoint essentially doubles the on-disk size of the index, which can lead to large and abrupt increases in disk usage (and perhaps long delays on occasion). To mitigate this problem to some degree, divide larger splitpoints into four equal phases. This means that, for example, instead of growing from 4GB to 8GB all at once, a hash index will now grow from 4GB to 5GB to 6GB to 7GB to 8GB, which is perhaps still not as smooth as we'd like but certainly an improvement. This changes the on-disk format of the metapage, so bump HASH_VERSION from 2 to 3. This will force a REINDEX of all existing hash indexes, but that's probably a good idea anyway. First, hash indexes from pre-10 versions of PostgreSQL could easily be corrupted, and we don't want to confuse corruption carried over from an older release with any corruption caused despite the new write-ahead logging in v10. Second, it will let us remove some backward-compatibility code added by commit 293e24e507838733aba4748b514536af2d39d7f2. Mithun Cy, reviewed by Amit Kapila, Jesper Pedersen and me. Regression test outputs updated by me. Discussion: http://postgr.es/m/CAD__OuhG6F1gQLCgMQNnMNgoCvOLQZz9zKYJQNYvYmmJoM42gA@mail.gmail.com Discussion: http://postgr.es/m/CA+TgmoYty0jCf-pa+m+vYUJ716+AxM7nv_syvyanyf5O-L_i2A@mail.gmail.com
The warning about hash indexes not being write-ahead logged and their use being discouraged has been removed. "snapshot too old" is now supported for tables with hash indexes. Most importantly, barring bugs, hash indexes will now be crash-safe and usable on standbys. This commit doesn't yet add WAL consistency checking for hash indexes, as we now have for other index types; a separate patch has been submitted to cure that lack. Amit Kapila, reviewed and slightly modified by me. The larger patch series of which this is a part has been reviewed and tested by Álvaro Herrera, Ashutosh Sharma, Mark Kirkwood, Jeff Janes, and Jesper Pedersen. Discussion: http://postgr.es/m/CAA4eK1JOBX=YU33631Qh-XivYXtPSALh514+jR8XeD7v+K3r_Q@mail.gmail.com