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| author | Thomas Munro <tmunro@postgresql.org> | 2019-06-28 11:11:26 +1200 |
|---|---|---|
| committer | Thomas Munro <tmunro@postgresql.org> | 2019-06-28 17:13:08 +1200 |
| commit | 74b7cc8c02137f059703972aa14445b1e073f005 (patch) | |
| tree | 6376dddfc3b1f957d112c928b9db1c25192d0ec9 /src/backend/executor/nodeIndexonlyscan.c | |
| parent | 69fd82fedd746b82427097883daf2921dd77584e (diff) | |
| download | postgresql-74b7cc8c02137f059703972aa14445b1e073f005.tar.gz postgresql-74b7cc8c02137f059703972aa14445b1e073f005.zip | |
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.
Reviewed-by: Ashwin Agrawal
Discussion: https://postgr.es/m/CAEepm%3D2GK3FVdnt5V3d%2Bh9njWipCv_fNL%3DwjxyUhzsF%3D0PcbNg%40mail.gmail.com
Diffstat (limited to 'src/backend/executor/nodeIndexonlyscan.c')
| -rw-r--r-- | src/backend/executor/nodeIndexonlyscan.c | 7 |
1 files changed, 2 insertions, 5 deletions
diff --git a/src/backend/executor/nodeIndexonlyscan.c b/src/backend/executor/nodeIndexonlyscan.c index 8a4d795d1a9..f0f8fa210ba 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, |