mirror of
https://github.com/postgres/postgres.git
synced 2025-07-14 08:21:07 +03:00
Cache eval cost of qualification expressions in RestrictInfo nodes to
avoid repeated evaluations in cost_qual_eval(). This turns out to save a useful fraction of planning time. No change to external representation of RestrictInfo --- although that node type doesn't appear in stored rules anyway.
This commit is contained in:
@ -42,7 +42,7 @@
|
||||
* Portions Copyright (c) 1994, Regents of the University of California
|
||||
*
|
||||
* IDENTIFICATION
|
||||
* $Header: /cvsroot/pgsql/src/backend/optimizer/path/costsize.c,v 1.64 2000/10/05 19:48:26 momjian Exp $
|
||||
* $Header: /cvsroot/pgsql/src/backend/optimizer/path/costsize.c,v 1.65 2000/12/12 23:33:33 tgl Exp $
|
||||
*
|
||||
*-------------------------------------------------------------------------
|
||||
*/
|
||||
@ -672,8 +672,38 @@ Cost
|
||||
cost_qual_eval(List *quals)
|
||||
{
|
||||
Cost total = 0;
|
||||
List *l;
|
||||
|
||||
cost_qual_eval_walker((Node *) quals, &total);
|
||||
/* We don't charge any cost for the implicit ANDing at top level ... */
|
||||
|
||||
foreach(l, quals)
|
||||
{
|
||||
Node *qual = (Node *) lfirst(l);
|
||||
|
||||
/*
|
||||
* RestrictInfo nodes contain an eval_cost field reserved for this
|
||||
* routine's use, so that it's not necessary to evaluate the qual
|
||||
* clause's cost more than once. If the clause's cost hasn't been
|
||||
* computed yet, the field will contain -1.
|
||||
*/
|
||||
if (qual && IsA(qual, RestrictInfo))
|
||||
{
|
||||
RestrictInfo *restrictinfo = (RestrictInfo *) qual;
|
||||
|
||||
if (restrictinfo->eval_cost < 0)
|
||||
{
|
||||
restrictinfo->eval_cost = 0;
|
||||
cost_qual_eval_walker((Node *) restrictinfo->clause,
|
||||
&restrictinfo->eval_cost);
|
||||
}
|
||||
total += restrictinfo->eval_cost;
|
||||
}
|
||||
else
|
||||
{
|
||||
/* If it's a bare expression, must always do it the hard way */
|
||||
cost_qual_eval_walker(qual, &total);
|
||||
}
|
||||
}
|
||||
return total;
|
||||
}
|
||||
|
||||
@ -748,18 +778,6 @@ cost_qual_eval_walker(Node *node, Cost *total)
|
||||
}
|
||||
/* fall through to examine args of Expr node */
|
||||
}
|
||||
|
||||
/*
|
||||
* expression_tree_walker doesn't know what to do with RestrictInfo
|
||||
* nodes, but we just want to recurse through them.
|
||||
*/
|
||||
if (IsA(node, RestrictInfo))
|
||||
{
|
||||
RestrictInfo *restrictinfo = (RestrictInfo *) node;
|
||||
|
||||
return cost_qual_eval_walker((Node *) restrictinfo->clause, total);
|
||||
}
|
||||
/* Otherwise, recurse. */
|
||||
return expression_tree_walker(node, cost_qual_eval_walker,
|
||||
(void *) total);
|
||||
}
|
||||
|
@ -8,7 +8,7 @@
|
||||
*
|
||||
*
|
||||
* IDENTIFICATION
|
||||
* $Header: /cvsroot/pgsql/src/backend/optimizer/plan/initsplan.c,v 1.53 2000/11/23 03:57:31 tgl Exp $
|
||||
* $Header: /cvsroot/pgsql/src/backend/optimizer/plan/initsplan.c,v 1.54 2000/12/12 23:33:33 tgl Exp $
|
||||
*
|
||||
*-------------------------------------------------------------------------
|
||||
*/
|
||||
@ -338,6 +338,7 @@ distribute_qual_to_rels(Query *root, Node *clause,
|
||||
bool can_be_equijoin;
|
||||
|
||||
restrictinfo->clause = (Expr *) clause;
|
||||
restrictinfo->eval_cost = -1; /* not computed until needed */
|
||||
restrictinfo->subclauseindices = NIL;
|
||||
restrictinfo->mergejoinoperator = InvalidOid;
|
||||
restrictinfo->left_sortop = InvalidOid;
|
||||
|
@ -14,7 +14,7 @@
|
||||
*
|
||||
*
|
||||
* IDENTIFICATION
|
||||
* $Header: /cvsroot/pgsql/src/backend/optimizer/prep/prepunion.c,v 1.56 2000/11/12 00:36:59 tgl Exp $
|
||||
* $Header: /cvsroot/pgsql/src/backend/optimizer/prep/prepunion.c,v 1.57 2000/12/12 23:33:34 tgl Exp $
|
||||
*
|
||||
*-------------------------------------------------------------------------
|
||||
*/
|
||||
@ -652,7 +652,7 @@ adjust_inherited_attrs_mutator(Node *node,
|
||||
/*
|
||||
* We have to process RestrictInfo nodes specially: we do NOT want to
|
||||
* copy the original subclauseindices list, since the new rel may have
|
||||
* different indices. The list will be rebuilt during planning anyway.
|
||||
* different indices. The list will be rebuilt during later planning.
|
||||
*/
|
||||
if (IsA(node, RestrictInfo))
|
||||
{
|
||||
@ -666,6 +666,7 @@ adjust_inherited_attrs_mutator(Node *node,
|
||||
adjust_inherited_attrs_mutator((Node *) oldinfo->clause, context);
|
||||
|
||||
newinfo->subclauseindices = NIL;
|
||||
newinfo->eval_cost = -1; /* reset this too */
|
||||
|
||||
return (Node *) newinfo;
|
||||
}
|
||||
|
Reference in New Issue
Block a user