diff options
Diffstat (limited to 'src/backend/executor/nodeHashjoin.c')
| -rw-r--r-- | src/backend/executor/nodeHashjoin.c | 29 |
1 files changed, 24 insertions, 5 deletions
diff --git a/src/backend/executor/nodeHashjoin.c b/src/backend/executor/nodeHashjoin.c index ad0c302e029..aea2ab3e4fd 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 1.97 2009/01/01 17:23:41 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/executor/nodeHashjoin.c,v 1.98 2009/03/21 00:04:38 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -198,19 +198,23 @@ ExecHashJoin(HashJoinState *node) node->hj_MatchedOuter = false; /* - * now we have an outer tuple, find the corresponding bucket for - * this tuple from the hash table + * Now we have an outer tuple; find the corresponding bucket for + * this tuple in the main hash table or skew hash table. */ node->hj_CurHashValue = hashvalue; ExecHashGetBucketAndBatch(hashtable, hashvalue, &node->hj_CurBucketNo, &batchno); + node->hj_CurSkewBucketNo = ExecHashGetSkewBucket(hashtable, + hashvalue); node->hj_CurTuple = NULL; /* * Now we've got an outer tuple and the corresponding hash bucket, - * but this tuple may not belong to the current batch. + * but it might not belong to the current batch, or it might + * match a skew bucket. */ - if (batchno != hashtable->curbatch) + if (batchno != hashtable->curbatch && + node->hj_CurSkewBucketNo == INVALID_SKEW_BUCKET_NO) { /* * Need to postpone this outer tuple to a later batch. Save it @@ -452,6 +456,7 @@ ExecInitHashJoin(HashJoin *node, EState *estate, int eflags) hjstate->hj_CurHashValue = 0; hjstate->hj_CurBucketNo = 0; + hjstate->hj_CurSkewBucketNo = INVALID_SKEW_BUCKET_NO; hjstate->hj_CurTuple = NULL; /* @@ -651,6 +656,19 @@ start_over: BufFileClose(hashtable->outerBatchFile[curbatch]); hashtable->outerBatchFile[curbatch] = NULL; } + else /* we just finished the first batch */ + { + /* + * Reset some of the skew optimization state variables, since we + * no longer need to consider skew tuples after the first batch. + * The memory context reset we are about to do will release the + * skew hashtable itself. + */ + hashtable->skewEnabled = false; + hashtable->skewBucket = NULL; + hashtable->skewBucketNums = NULL; + hashtable->spaceUsedSkew = 0; + } /* * We can always skip over any batches that are completely empty on both @@ -880,6 +898,7 @@ ExecReScanHashJoin(HashJoinState *node, ExprContext *exprCtxt) /* Always reset intra-tuple state */ node->hj_CurHashValue = 0; node->hj_CurBucketNo = 0; + node->hj_CurSkewBucketNo = INVALID_SKEW_BUCKET_NO; node->hj_CurTuple = NULL; node->js.ps.ps_TupFromTlist = false; |