Re: Ignoring BRIN for HOT updates (was: -udpates seems broken)
Matthias van de Meent <boekewurm+postgres@gmail.com>
From: Matthias van de Meent <boekewurm+postgres@gmail.com>
To: Tomas Vondra <tomas.vondra@enterprisedb.com>
Cc: Michael Paquier <michael@paquier.xyz>,
Robert Haas <robertmhaas@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2023-02-22T13:14:02Z
Lists: pgsql-hackers
Attachments
- v4-0001-Ignore-BRIN-indexes-when-checking-for-HOT-updates.patch (application/octet-stream) patch v4-0001
On Wed, 22 Feb 2023 at 13:15, Tomas Vondra <tomas.vondra@enterprisedb.com> wrote: > > On 2/20/23 19:15, Matthias van de Meent wrote: > > Thanks. Based on feedback, attached is v2 of the patch, with as > > significant changes: > > > > - We don't store the columns we mention in predicates of summarized > > indexes in the hotblocking column anymore, they are stored in the > > summarized columns bitmap instead. This further reduces the chance of > > failiing to apply HOT with summarizing indexes. > > Interesting idea. I need to think about the correctness, but AFAICS it > should work. Do we have any tests covering such cases? There is a test that checks that an update to the predicated column does update the index (on table brin_hot_2). However, the description was out of date, so I've updated that in v4. > > - The heaptuple header bit for summarized update in inserted tuples is > > replaced with passing an out parameter. This simplifies the logic and > > decreases chances of accidentally storing incorrect data. > > > > OK. > > 0002 proposes a minor RelationGetIndexPredicate() tweak, getting rid of > the repeated if/else branches. Feel free to discard, if you think the v2 > approach is better. I agree that this is better, it's included in v4 of the patch, as attached. Kind regards, Matthias van de Meent.
Commits
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API reference →
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Ignore BRIN indexes when checking for HOT updates
- 19d8e2308bc5 16.0 landed
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Revert changes in HOT handling of BRIN indexes
- e3fcca0d0d24 15.0 landed
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Ignore BRIN indexes when checking for HOT udpates
- 5753d4ee320b 15.0 cited