Re: Making Row Comparison NULL row member handling more robust during skip scans

Peter Geoghegan <pg@bowt.ie>

From: Peter Geoghegan <pg@bowt.ie>

To: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>

Date: 2025-07-01T16:37:05Z

Lists: pgsql-hackers

Attachments

v5-0001-Make-handling-of-redundant-nbtree-keys-more-robus.patch (application/octet-stream) patch v5-0001
v5-0002-Make-row-compares-robust-during-scans-with-arrays.patch (application/octet-stream) patch v5-0002

On Fri, Jun 27, 2025 at 5:35 PM Peter Geoghegan <pg@bowt.ie> wrote:
> Attached is v4, which is largely just a polished version of v3. It has
> improved comments and more worked out commit messages. Plus the second
> patch (the row compare patch) now teaches _bt_first to fully rely on
> scan key requiredness markings, just like with other scan keys.

Heikki said he'd be able to give this patch set at least a quick
review, so here's a new revision, v4.

This isn't really different to v4. It has more comment cleanup, and
better commit messages.

-- 
Peter Geoghegan

Commits

Make row compares robust during nbtree array scans.
- bd3f59fdb717 19 (unreleased) landed
- 4cb889d21f3d 18.0 landed
Make handling of redundant nbtree keys more robust.
- f09816a0a7c1 19 (unreleased) landed
- 7c365eb50429 18.0 landed
Revert "nbtree: Remove useless row compare arg."
- dd2ce3792754 18.0 cited
nbtree: Remove useless row compare arg.
- 54c6ea8c81db 18.0 cited
Prevent premature nbtree array advancement.
- 5f4d98d4f371 18.0 cited
Improvements and fixes for e0b1ee17dc
- 7e6fb5da41d8 17.0 cited
Fix incorrect handling of NULL index entries in indexed ROW() comparisons.
- a298a1e06fb0 9.6.0 cited
Fix btree stop-at-nulls logic properly.
- 882368e854b6 9.2.0 cited
Stop btree indexscans upon reaching nulls in either direction.
- 6980f817e83c 9.2.0 cited