From 87eb25535d0db49fec9b3ddb2f1c4dfd97c8805e Mon Sep 17 00:00:00 2001 From: Peter Geoghegan Date: Wed, 29 Jul 2020 16:00:54 -0700 Subject: [PATCH] Backpatch tuplesort.c assertion. Backpatch an assertion (that was originally added to Postgres 12 by commit dd299df8189) that seems broadly useful. The assertion can detect violations of the HOT invariant (i.e. no two index tuples can point to the same heap TID) when CREATE INDEX somehow incorrectly allows that to take place. For example, a IndexBuildHeapScan/heapam_index_build_range_scan bug might result in two tuples that both point to the same heap TID. If these two tuples also happen to be duplicates, the assertion will fail. Discussion: https://postgr.es/m/CAH2-WzmBxu4o=pMsniur+bwHqCGCmV_AOLkuK6BuU7ngA6evqw@mail.gmail.com Backpatch: 9.5-11 only --- src/backend/utils/sort/tuplesort.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/src/backend/utils/sort/tuplesort.c b/src/backend/utils/sort/tuplesort.c index 549baf4b4f..f770b570eb 100644 --- a/src/backend/utils/sort/tuplesort.c +++ b/src/backend/utils/sort/tuplesort.c @@ -4076,6 +4076,9 @@ comparetup_index_btree(const SortTuple *a, const SortTuple *b, return (pos1 < pos2) ? -1 : 1; } + /* ItemPointer values should never be equal */ + Assert(false); + return 0; } @@ -4128,6 +4131,9 @@ comparetup_index_hash(const SortTuple *a, const SortTuple *b, return (pos1 < pos2) ? -1 : 1; } + /* ItemPointer values should never be equal */ + Assert(false); + return 0; }