EUC_* ILIKE index scan stopped matching seq scan in v19

Started by Noah Misch2 months ago3 messageshackers
Beta feature

Hackorum builds and tests every patch posted to the lists, not only commitfest submissions. This is Hackorum's own CI rather than the PostgreSQL project's, and it is still under testing - please report anything that looks wrong.

won't retrysuccessCI history

This thread has been committed, so CI has stopped here. Anything below is the last result it produced.

You can run a PostgreSQL built from this patch straight from Docker, with no checkout and no build:

docker run --rm -p 5432:5432 ghcr.io/hackorum-dev/postgres-patch:t253561
psql -h localhost -U postgres

Built from patchset v2 (message #2), September 09, 2026 at 02:28 PM.

Every patchset is also pushed to a branch of our PostgreSQL fork, so you can check out the same tree CI built. Without a PostgreSQL checkout:

git clone --branch t253561_2 https://github.com/hackorum-dev/postgres.git

In a checkout you already have, add the fork once:

git remote add hackorum https://github.com/hackorum-dev/postgres.git

then, for this patchset and every later one:

git fetch hackorum t253561_2 && git checkout t253561_2

Patchset v2 (message #2) is on t253561_2

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#1Noah Misch
noah@leadboat.com

Opus 5 found the $SUBJECT regression from commit 630706c "Add pg_iswcased()".
That finding still holds at today's master. I am attaching the LLM's report
and test case.

Attachments:

630706c-EUC-ILIKE-test-v0.patchtext/plain; charset=utf-8Download+647-0
#2Jeff Davis
pgsql@j-davis.com
In reply to: Noah Misch (#1)
Re: EUC_* ILIKE index scan stopped matching seq scan in v19

On Wed, 2026-08-26 at 15:15 -0700, Noah Misch wrote:

Opus 5 found the $SUBJECT regression from commit 630706c "Add
pg_iswcased()".
That finding still holds at today's master.  I am attaching the LLM's
report
and test case.

Thank you for the report. Patch attached.

I can add a test or two, but they'd be fairly heavyweight and platform-
specific, I think.

Regards,
Jeff Davis

Attachments:

t253561_2
v1-0001-Fix-pg_iswcased.patchtext/x-patch; charset=UTF-8; name=v1-0001-Fix-pg_iswcased.patchDownload+52-6
#3Jeff Davis
pgsql@j-davis.com
In reply to: Jeff Davis (#2)
Re: EUC_* ILIKE index scan stopped matching seq scan in v19

On Tue, 2026-09-01 at 15:51 -0700, Jeff Davis wrote:

Thank you for the report. Patch attached.

Committed.

Regards,
Jeff Davis