Horton

Reject oversized MCV lists in pg_restore_extended_stats()

Michael Paquier <michael@paquier.xyz>

View on postgr.es
Commit: f6e4ec0a705b180f29e4910dd5297b815a260eec
Author: Michael Paquier <michael@paquier.xyz>
Date: 2026-06-16T06:14:58Z
Releases: 19 (unreleased) 
Reject oversized MCV lists in pg_restore_extended_stats()

import_mcv(), called by pg_restore_extended_stats(), allowed a list of
MCV items to be larger than the maximum supported when the stats are
loaded back in statext_mcv_deserialize() (STATS_MCVLIST_MAX_ITEMS or 10k
items).  A follow-up attempt at loading them would cause a failure,
statext_mcv_deserialize() blocking any attempts.

Attempts at restoring MCV lists too long are now rejected, generating a
WARNING like other inconsistent inputs.

Author: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/CAON2xHORd2ESXm1KcVeeZ0Kd_aJk4dL4M2WLtzVDM4puaZ-20w@mail.gmail.com

Files

PathChange+/−
src/backend/statistics/extended_stats_funcs.c modified +15 −0
src/test/regress/expected/stats_import.out modified +19 −0
src/test/regress/sql/stats_import.sql modified +14 −0

Discussion