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authorTomas Vondra2022-12-30 18:44:48 +0000
committerTomas Vondra2022-12-30 19:49:50 +0000
commit02699bc1fd3b7fccba2e6b55189a148ef69b8a00 (patch)
tree7e775da8a089eded9e56d8cd95e3f8696947bc5a
parent7aa81c61ec8f68212570192f3088544dbfa43cb9 (diff)
Fix assert in BRIN build_distances
When brin_minmax_multi_union merges summaries, we may end up with just a single range after merge_overlapping_ranges. The summaries may contain just one range each, and they may overlap (or be exactly the same). With a single range there's no distance to calculate, but we happen to call build_distances anyway - which is fine, we don't calculate the distance in this case, except that with asserts this failed due to a check there are at least two ranges. The assert is unnecessarily strict, so relax it a bit and bail out if there's just a single range. The relaxed assert would be enough, but this way we don't allocate unnecessary memory for distance. Backpatch to 14, where minmax-multi opclasses were introduced. Reported-by: Jaime Casanova Backpatch-through: 14 Discussion: https://postgr.es/m/YzVA55qS0hgz8P3r@ahch-to
-rw-r--r--src/backend/access/brin/brin_minmax_multi.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/src/backend/access/brin/brin_minmax_multi.c b/src/backend/access/brin/brin_minmax_multi.c
index 9a0bcf6698..def864e2fa 100644
--- a/src/backend/access/brin/brin_minmax_multi.c
+++ b/src/backend/access/brin/brin_minmax_multi.c
@@ -1335,7 +1335,11 @@ build_distances(FmgrInfo *distanceFn, Oid colloid,
int ndistances;
DistanceValue *distances;
- Assert(neranges >= 2);
+ Assert(neranges > 0);
+
+ /* If there's only a single range, there's no distance to calculate. */
+ if (neranges == 1)
+ return NULL;
ndistances = (neranges - 1);
distances = (DistanceValue *) palloc0(sizeof(DistanceValue) * ndistances);