Horton

pg_plan_advice: Handle non-repeatable TABLESAMPLE scans.

Robert Haas <rhaas@postgresql.org>

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Commit: 3311ccc3d24bf83fb26a8af81ea68a8fcc295c26
Author: Robert Haas <rhaas@postgresql.org>
Date: 2026-04-13T12:46:25Z
Releases: 19 (unreleased) 
pg_plan_advice: Handle non-repeatable TABLESAMPLE scans.

When a tablesample routine says that it is not repeatable across
scans, set_tablesample_rel_pathlist will (usually) materialize it,
confusing pg_plan_advice's plan walker machinery. To fix, update that
machinery to view such Material paths as essentially an extension of
the underlying scan.

Reported-by: Alexander Lakhin <exclusion@gmail.com>
Discussion: http://postgr.es/m/CA+TgmobOOmmXSJz3e+cjTY-bA1+W0dqVDqzxUBEvGtW62whYGg@mail.gmail.com

Files

PathChange+/−
contrib/pg_plan_advice/expected/scan.out modified +38 −0
contrib/pg_plan_advice/Makefile modified +2 −0
contrib/pg_plan_advice/pgpa_join.c modified +8 −4
contrib/pg_plan_advice/pgpa_scan.c modified +11 −0
contrib/pg_plan_advice/pgpa_walker.c modified +29 −0
contrib/pg_plan_advice/pgpa_walker.h modified +1 −0
contrib/pg_plan_advice/sql/scan.sql modified +12 −0

Discussion