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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2000-12-14 22:30:45 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2000-12-14 22:30:45 +0000 |
| commit | ea166f11462c863d91378fcbb15d4d3140002413 (patch) | |
| tree | ef157dad5b07081aae231ab9691f2ef2d5b625a4 /src/backend/optimizer/prep/prepunion.c | |
| parent | db11f4382abad09d42e784c1fa19dfbcd68038ac (diff) | |
| download | postgresql-ea166f11462c863d91378fcbb15d4d3140002413.tar.gz postgresql-ea166f11462c863d91378fcbb15d4d3140002413.zip | |
Planner speedup hacking. Avoid saving useless pathkeys, so that path
comparison does not consider paths different when they differ only in
uninteresting aspects of sort order. (We had a special case of this
consideration for indexscans already, but generalize it to apply to
ordered join paths too.) Be stricter about what is a canonical pathkey
to allow faster pathkey comparison. Cache canonical pathkeys and
dispersion stats for left and right sides of a RestrictInfo's clause,
to avoid repeated computation. Total speedup will depend on number of
tables in a query, but I see about 4x speedup of planning phase for
a sample seven-table query.
Diffstat (limited to 'src/backend/optimizer/prep/prepunion.c')
| -rw-r--r-- | src/backend/optimizer/prep/prepunion.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/src/backend/optimizer/prep/prepunion.c b/src/backend/optimizer/prep/prepunion.c index d52ed8fb923..5da3c1e7388 100644 --- a/src/backend/optimizer/prep/prepunion.c +++ b/src/backend/optimizer/prep/prepunion.c @@ -14,7 +14,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/optimizer/prep/prepunion.c,v 1.57 2000/12/12 23:33:34 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/prep/prepunion.c,v 1.58 2000/12/14 22:30:44 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -667,6 +667,10 @@ adjust_inherited_attrs_mutator(Node *node, newinfo->subclauseindices = NIL; newinfo->eval_cost = -1; /* reset this too */ + newinfo->left_pathkey = NIL; /* and these */ + newinfo->right_pathkey = NIL; + newinfo->left_dispersion = -1; + newinfo->right_dispersion = -1; return (Node *) newinfo; } |