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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2011-10-23 00:43:45 -0400 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2011-10-23 00:43:45 -0400 |
| commit | 18661c67e96ff4a81ab3844843a73676d161db0c (patch) | |
| tree | 6cc45485bd8ffda5563a07c9c2fa477d247b7711 /src/backend/optimizer/path/indxpath.c | |
| parent | 8e8ac0894b196c4dd8618bca1f598f13bf5e18ea (diff) | |
| download | postgresql-18661c67e96ff4a81ab3844843a73676d161db0c.tar.gz postgresql-18661c67e96ff4a81ab3844843a73676d161db0c.zip | |
Don't trust deferred-unique indexes for join removal.
The uniqueness condition might fail to hold intra-transaction, and assuming
it does can give incorrect query results. Per report from Marti Raudsepp,
though this is not his proposed patch.
Back-patch to 9.0, where both these features were introduced. In the
released branches, add the new IndexOptInfo field to the end of the struct,
to try to minimize ABI breakage for third-party code that may be examining
that struct.
Diffstat (limited to 'src/backend/optimizer/path/indxpath.c')
| -rw-r--r-- | src/backend/optimizer/path/indxpath.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/src/backend/optimizer/path/indxpath.c b/src/backend/optimizer/path/indxpath.c index fc96f4f1dac..58b8797b738 100644 --- a/src/backend/optimizer/path/indxpath.c +++ b/src/backend/optimizer/path/indxpath.c @@ -2179,10 +2179,11 @@ relation_has_unique_index_for(PlannerInfo *root, RelOptInfo *rel, int c; /* - * If the index is not unique or if it's a partial index that doesn't - * match the query, it's useless here. + * If the index is not unique, or not immediately enforced, or if it's + * a partial index that doesn't match the query, it's useless here. */ - if (!ind->unique || (ind->indpred != NIL && !ind->predOK)) + if (!ind->unique || !ind->immediate || + (ind->indpred != NIL && !ind->predOK)) continue; /* |