diff options
| -rw-r--r-- | src/backend/nodes/outfuncs.c | 3 | ||||
| -rw-r--r-- | src/backend/optimizer/path/costsize.c | 4 | ||||
| -rw-r--r-- | src/backend/optimizer/plan/createplan.c | 6 | ||||
| -rw-r--r-- | src/backend/optimizer/util/pathnode.c | 15 | ||||
| -rw-r--r-- | src/include/nodes/relation.h | 3 |
5 files changed, 25 insertions, 6 deletions
diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c index 212fc0673c2..3fdd9bab669 100644 --- a/src/backend/nodes/outfuncs.c +++ b/src/backend/nodes/outfuncs.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/nodes/outfuncs.c,v 1.355 2009/03/21 00:04:39 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/nodes/outfuncs.c,v 1.356 2009/03/26 17:15:34 tgl Exp $ * * NOTES * Every node type that can appear in stored rules' parsetrees *must* @@ -1448,6 +1448,7 @@ _outHashPath(StringInfo str, HashPath *node) _outJoinPathInfo(str, (JoinPath *) node); WRITE_NODE_FIELD(path_hashclauses); + WRITE_INT_FIELD(num_batches); } static void diff --git a/src/backend/optimizer/path/costsize.c b/src/backend/optimizer/path/costsize.c index b07a2599bbe..2b3cf61e751 100644 --- a/src/backend/optimizer/path/costsize.c +++ b/src/backend/optimizer/path/costsize.c @@ -54,7 +54,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/optimizer/path/costsize.c,v 1.205 2009/03/21 00:04:39 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/optimizer/path/costsize.c,v 1.206 2009/03/26 17:15:35 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -1880,6 +1880,8 @@ cost_hashjoin(HashPath *path, PlannerInfo *root, SpecialJoinInfo *sjinfo) &numbatches, &num_skew_mcvs); virtualbuckets = (double) numbuckets *(double) numbatches; + /* mark the path with estimated # of batches */ + path->num_batches = numbatches; /* * Determine bucketsize fraction for inner relation. We use the smallest diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c index be4d79f1bf2..cff0424c6c7 100644 --- a/src/backend/optimizer/plan/createplan.c +++ b/src/backend/optimizer/plan/createplan.c @@ -10,7 +10,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/optimizer/plan/createplan.c,v 1.256 2009/03/21 00:04:39 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/optimizer/plan/createplan.c,v 1.257 2009/03/26 17:15:35 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -1910,6 +1910,10 @@ create_hashjoin_plan(PlannerInfo *root, /* We don't want any excess columns in the hashed tuples */ disuse_physical_tlist(inner_plan, best_path->jpath.innerjoinpath); + /* If we expect batching, suppress excess columns in outer tuples too */ + if (best_path->num_batches > 1) + disuse_physical_tlist(outer_plan, best_path->jpath.outerjoinpath); + /* * If there is a single join clause and we can identify the outer * variable as a simple column reference, supply its identity for diff --git a/src/backend/optimizer/util/pathnode.c b/src/backend/optimizer/util/pathnode.c index 28b2828c2dd..5ba413bb1ad 100644 --- a/src/backend/optimizer/util/pathnode.c +++ b/src/backend/optimizer/util/pathnode.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/optimizer/util/pathnode.c,v 1.150 2009/02/27 00:06:27 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/optimizer/util/pathnode.c,v 1.151 2009/03/26 17:15:35 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -1480,9 +1480,20 @@ create_hashjoin_path(PlannerInfo *root, pathnode->jpath.outerjoinpath = outer_path; pathnode->jpath.innerjoinpath = inner_path; pathnode->jpath.joinrestrictinfo = restrict_clauses; - /* A hashjoin never has pathkeys, since its ordering is unpredictable */ + /* + * A hashjoin never has pathkeys, since its output ordering is + * unpredictable due to possible batching. XXX If the inner relation is + * small enough, we could instruct the executor that it must not batch, + * and then we could assume that the output inherits the outer relation's + * ordering, which might save a sort step. However there is considerable + * downside if our estimate of the inner relation size is badly off. + * For the moment we don't risk it. (Note also that if we wanted to take + * this seriously, joinpath.c would have to consider many more paths for + * the outer rel than it does now.) + */ pathnode->jpath.path.pathkeys = NIL; pathnode->path_hashclauses = hashclauses; + /* cost_hashjoin will fill in pathnode->num_batches */ cost_hashjoin(pathnode, root, sjinfo); diff --git a/src/include/nodes/relation.h b/src/include/nodes/relation.h index 4f1bc4067d2..cf567b99746 100644 --- a/src/include/nodes/relation.h +++ b/src/include/nodes/relation.h @@ -7,7 +7,7 @@ * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/include/nodes/relation.h,v 1.170 2009/03/05 23:06:45 tgl Exp $ + * $PostgreSQL: pgsql/src/include/nodes/relation.h,v 1.171 2009/03/26 17:15:35 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -845,6 +845,7 @@ typedef struct HashPath { JoinPath jpath; List *path_hashclauses; /* join clauses used for hashing */ + int num_batches; /* number of batches expected */ } HashPath; /* |