diff options
| 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/nodes/readfuncs.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/nodes/readfuncs.c')
| -rw-r--r-- | src/backend/nodes/readfuncs.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/src/backend/nodes/readfuncs.c b/src/backend/nodes/readfuncs.c index d8aa2a5d2dc..4d4ec782e7a 100644 --- a/src/backend/nodes/readfuncs.c +++ b/src/backend/nodes/readfuncs.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/nodes/readfuncs.c,v 1.101 2000/12/12 23:33:33 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/nodes/readfuncs.c,v 1.102 2000/12/14 22:30:42 tgl Exp $ * * NOTES * Most of the read functions for plan nodes are tested. (In fact, they @@ -1848,6 +1848,11 @@ _readRestrictInfo(void) /* eval_cost is not part of saved representation; compute on first use */ local_node->eval_cost = -1; + /* ditto for cached pathkeys and dispersion */ + local_node->left_pathkey = NIL; + local_node->right_pathkey = NIL; + local_node->left_dispersion = -1; + local_node->right_dispersion = -1; return local_node; } |