From 3097e1b7973e83b7ce05e5c81e3696852c0a7806 Mon Sep 17 00:00:00 2001 From: Thomas Munro Date: Fri, 28 Jun 2019 11:11:26 +1200 Subject: [PATCH] Fix misleading comment in nodeIndexonlyscan.c. The stated reason for acquiring predicate locks on heap pages hasn't existed since commit c01262a8, so fix the comment. Perhaps in a later release we'll also be able to change the code to use tuple locks. Back-patch all the way. Discussion: https://postgr.es/m/CAEepm%3D2GK3FVdnt5V3d%2Bh9njWipCv_fNL%3DwjxyUhzsF%3D0PcbNg%40mail.gmail.com --- src/backend/executor/nodeIndexonlyscan.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/src/backend/executor/nodeIndexonlyscan.c b/src/backend/executor/nodeIndexonlyscan.c index 8a4d795d1a..f0f8fa210b 100644 --- a/src/backend/executor/nodeIndexonlyscan.c +++ b/src/backend/executor/nodeIndexonlyscan.c @@ -242,11 +242,8 @@ IndexOnlyNext(IndexOnlyScanState *node) errmsg("lossy distance functions are not supported in index-only scans"))); /* - * Predicate locks for index-only scans must be acquired at the page - * level when the heap is not accessed, since tuple-level predicate - * locks need the tuple's xmin value. If we had to visit the tuple - * anyway, then we already have the tuple-level lock and can skip the - * page lock. + * If we didn't access the heap, then we'll need to take a predicate + * lock explicitly, as if we had. For now we do that at page level. */ if (!tuple_from_heap) PredicateLockPage(scandesc->heapRelation, -- 2.21.0