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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2004-09-17 18:29:54 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2004-09-17 18:29:54 +0000 |
| commit | f4d5c52a83b9af2346e58c2e036469b8a14cabfa (patch) | |
| tree | 9f303e927441e6b36a6ca83626c9e3a8534b2139 | |
| parent | 3c06653fbd58d5e3708bb6b251e66321a35a5f39 (diff) | |
| download | postgresql-f4d5c52a83b9af2346e58c2e036469b8a14cabfa.tar.gz | |
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.
| -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 12f6d58443..7d3924b497 100644 --- a/src/backend/executor/nodeHashjoin.c +++ b/src/backend/executor/nodeHashjoin.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/executor/nodeHashjoin.c,v 1.38 2001/03/22 06:16:13 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/executor/nodeHashjoin.c,v 1.38.2.1 2004/09/17 18:29:54 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -575,12 +575,14 @@ 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; |