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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2004-09-17 18:28:53 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2004-09-17 18:28:53 +0000 |
| commit | a5713ec427f15f2c63eaed14f2a16a952b7ddf06 (patch) | |
| tree | ba8dc425608584922b7ca91ae20670ecf07be755 /src/backend/executor/nodeHashjoin.c | |
| parent | 054b78ba38e7bd11db1725ede38675b5cfaebe0b (diff) | |
| download | postgresql-a5713ec427f15f2c63eaed14f2a16a952b7ddf06.tar.gz postgresql-a5713ec427f15f2c63eaed14f2a16a952b7ddf06.zip | |
Hashed LEFT JOIN would miss outer tuples with no inner match if the join
was large enough to be batched and the tuples fell into a batch where
there were no inner tuples at all. Thanks to Xiaoyu Wang for finding a
test case that exposed this long-standing bug.
Diffstat (limited to 'src/backend/executor/nodeHashjoin.c')
| -rw-r--r-- | src/backend/executor/nodeHashjoin.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/src/backend/executor/nodeHashjoin.c b/src/backend/executor/nodeHashjoin.c index fbc55655714..53215be6e91 100644 --- a/src/backend/executor/nodeHashjoin.c +++ b/src/backend/executor/nodeHashjoin.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/executor/nodeHashjoin.c,v 1.64 2004/08/29 05:06:42 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/executor/nodeHashjoin.c,v 1.65 2004/09/17 18:28:53 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -603,12 +603,14 @@ ExecHashJoinNewBatch(HashJoinState *hjstate) } /* - * We can skip over any batches that are empty on either side. Release - * associated temp files right away. + * Normally we can skip over any batches that are empty on either side + * --- but for JOIN_LEFT, can only skip when left side is empty. + * Release associated temp files right away. */ while (newbatch <= nbatch && - (innerBatchSize[newbatch - 1] == 0L || - outerBatchSize[newbatch - 1] == 0L)) + (outerBatchSize[newbatch - 1] == 0L || + (innerBatchSize[newbatch - 1] == 0L && + hjstate->js.jointype != JOIN_LEFT))) { BufFileClose(hashtable->innerBatchFile[newbatch - 1]); hashtable->innerBatchFile[newbatch - 1] = NULL; |