Fix memory leak in Incremental Sort rescans The Incremental Sort had a couple issues, resulting in leaking memory during rescans, possibly triggering OOM. The code had a couple of related flaws:
1. During rescans, the sort states were reset but then also set to NULL (despite the comment saying otherwise). ExecIncrementalSort then sees NULL and initializes a new sort state, leaking the memory used by the old one. 2. Initializing the sort state also automatically rebuilt the info about presorted keys, leaking the already initialized info. presorted_keys was also unnecessarily reset to NULL. Patch by James Coleman, based on patches by Laurenz Albe and Tom Lane. Backpatch to 13, where Incremental Sort was introduced. Author: James Coleman, Laurenz Albe, Tom Lane Reported-by: Laurenz Albe, Zu-Ming Jiang Backpatch-through: 13 Discussion: https://postgr.es/m/b2bd02dff61af15e3526293e2771f874cf2a3be7.camel%40cybertec.at Discussion: https://postgr.es/m/db03c582-086d-e7cd-d4a1-3bc722f81765%40inf.ethz.ch Branch ------ REL_14_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/c1affa38c73b432d358c5b19b697e03a59b355ab Modified Files -------------- src/backend/executor/nodeIncrementalSort.c | 7 ------- 1 file changed, 7 deletions(-)