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pgsql: REPACK CONCURRENTLY: Initialize the range table more honestly 2+ messages / 1 participants [nested] [flat]
* pgsql: REPACK CONCURRENTLY: Initialize the range table more honestly @ 2026-07-03 18:06 Álvaro Herrera <alvherre@kurilemu.de> 0 siblings, 0 replies; 2+ messages in thread From: Álvaro Herrera @ 2026-07-03 18:06 UTC (permalink / raw) To: pgsql-committers@lists.postgresql.org REPACK CONCURRENTLY: Initialize the range table more honestly We were skipping a bunch of things that are mostly unnecessary for REPACK. However, one thing that seems would be better to pass closer to truth, is the updatedCols bitmapset in the range table entry for the repacked table. Cons up an RTE and install it into the EState. This only has an effect on btree indexes, because certain operations are optimized in the case of unchanged columns; and even then, correctnesss is not being compromised. The values we pass after this commit are not fully trustworthy either, because we simply say "all columns were updated" for all insert/updates, regardless of whether their values were actually modified or not. However, this way we err to the side of caution rather than to the opposite direction as we were originally doing. This could be refined in the future, but there's a trade-off: determining whether the column was in fact updated could be expensive. Author: Antonin Houska <ah@cybertec.at> Reviewed-by: Ewan Young <kdbase.hack@gmail.com> Backpatch-through: 19 Discussion: https://postgr.es/m/18222.1782126731@localhost Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/5ee9d7c299f2fe2f29db18c6448f798950efe22e Modified Files -------------- src/backend/commands/repack.c | 57 +++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 55 insertions(+), 2 deletions(-) ^ permalink raw reply [nested|flat] 2+ messages in thread
* pgsql: REPACK CONCURRENTLY: Initialize the range table more honestly @ 2026-07-03 18:06 Álvaro Herrera <alvherre@kurilemu.de> 0 siblings, 0 replies; 2+ messages in thread From: Álvaro Herrera @ 2026-07-03 18:06 UTC (permalink / raw) To: pgsql-committers@lists.postgresql.org REPACK CONCURRENTLY: Initialize the range table more honestly We were skipping a bunch of things that are mostly unnecessary for REPACK. However, one thing that seems would be better to pass closer to truth, is the updatedCols bitmapset in the range table entry for the repacked table. Cons up an RTE and install it into the EState. This only has an effect on btree indexes, because certain operations are optimized in the case of unchanged columns; and even then, correctnesss is not being compromised. The values we pass after this commit are not fully trustworthy either, because we simply say "all columns were updated" for all insert/updates, regardless of whether their values were actually modified or not. However, this way we err to the side of caution rather than to the opposite direction as we were originally doing. This could be refined in the future, but there's a trade-off: determining whether the column was in fact updated could be expensive. Author: Antonin Houska <ah@cybertec.at> Reviewed-by: Ewan Young <kdbase.hack@gmail.com> Backpatch-through: 19 Discussion: https://postgr.es/m/18222.1782126731@localhost Branch ------ REL_19_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/5e450df50dc8e688abbad229f174f006cc550388 Modified Files -------------- src/backend/commands/repack.c | 57 +++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 55 insertions(+), 2 deletions(-) ^ permalink raw reply [nested|flat] 2+ messages in thread
end of thread, other threads:[~2026-07-03 18:06 UTC | newest] Thread overview: 2+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2026-07-03 18:06 pgsql: REPACK CONCURRENTLY: Initialize the range table more honestly Álvaro Herrera <alvherre@kurilemu.de> 2026-07-03 18:06 pgsql: REPACK CONCURRENTLY: Initialize the range table more honestly Álvaro Herrera <alvherre@kurilemu.de>
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