database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-11-10 17:42:29 +03:00
Code Activity

Planner speedup hacking. Avoid saving useless pathkeys, so that path

Browse Source 
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.
This commit is contained in:
Tom Lane
2000-12-14 22:30:45 +00:00
parent db11f4382a
commit ea166f1146
16 changed files with 622 additions and 365 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
src/backend/nodes/equalfuncs.c
View File

@@ -20,7 +20,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v 1.84 2000/12/12 23:33:33 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v 1.85 2000/12/14 22:30:42 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -515,8 +515,9 @@ _equalRestrictInfo(RestrictInfo *a, RestrictInfo *b)
if (!equal(a->clause, b->clause))
return false;
/*
* ignore eval_cost, since it may not be set yet, and should be
* derivable from the clause anyway
* ignore eval_cost, left/right_pathkey, and left/right_dispersion,
* since they may not be set yet, and should be derivable from the
* clause anyway
*/
if (a->ispusheddown != b->ispusheddown)
return false;