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| author | David Rowley <drowley@postgresql.org> | 2021-11-24 14:57:07 +1300 |
|---|---|---|
| committer | David Rowley <drowley@postgresql.org> | 2021-11-24 14:57:07 +1300 |
| commit | f94edb06ab60545a0e9e90aedc39e3b81b2b9e3f (patch) | |
| tree | 4e0eda31256137faf25e4237ec527eb563dc4b19 /src/backend/nodes/bitmapset.c | |
| parent | 6c32c0977783fae217b5eaa1d22d26c96e5b0085 (diff) | |
Flush Memoize cache when non-key parameters change
It's possible that a subplan below a Memoize node contains a parameter
from above the Memoize node. If this parameter changes then cache entries
may become out-dated due to the new parameter value.
Previously Memoize was mistakenly not aware of this. We fix this here by
flushing the cache whenever a parameter that's not part of the cache
key changes.
Bug: #17213
Reported by: Elvis Pranskevichus
Author: David Rowley
Discussion: https://postgr.es/m/17213-988ed34b225a2862@postgresql.org
Backpatch-through: 14, where Memoize was added
Diffstat (limited to 'src/backend/nodes/bitmapset.c')
| -rw-r--r-- | src/backend/nodes/bitmapset.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/src/backend/nodes/bitmapset.c b/src/backend/nodes/bitmapset.c index 649478b0d4d..bff70cfb1ab 100644 --- a/src/backend/nodes/bitmapset.c +++ b/src/backend/nodes/bitmapset.c @@ -540,6 +540,8 @@ bms_overlap_list(const Bitmapset *a, const List *b) /* * bms_nonempty_difference - do sets have a nonempty difference? + * + * i.e., are any members set in 'a' that are not also set in 'b'. */ bool bms_nonempty_difference(const Bitmapset *a, const Bitmapset *b) |