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Make EXPLAIN results for Append, Group, Agg, Unique nodes more plausible.

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Group and Unique use an arbitrary assumption that there will be about
10% as many groups as input tuples --- perhaps someday we can refine this.
This commit is contained in:
Tom Lane
2000-02-03 06:12:19 +00:00
parent 40055db1eb
commit d24ef0d08f
2 changed files with 59 additions and 35 deletions
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35
src/backend/optimizer/prep/prepunion.c
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@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/prep/prepunion.c,v 1.42 2000/01/27 18:11:32 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/prep/prepunion.c,v 1.43 2000/02/03 06:12:19 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -218,11 +218,11 @@ plan_union_queries(Query *parse)
parse->havingQual = NULL;
parse->hasAggs = false;
return (make_append(union_plans,
union_rts,
0,
NULL,
parse->targetList));
return make_append(union_plans,
union_rts,
0,
NULL,
parse->targetList);
}
@ -272,11 +272,11 @@ plan_inherit_queries(Query *parse, List *tlist, Index rt_index)
union_plans = plan_inherit_query(union_relids, rt_index, rt_entry,
parse, tlist, &inheritrtable);
return (make_append(union_plans,
NULL,
rt_index,
inheritrtable,
((Plan *) lfirst(union_plans))->targetlist));
return make_append(union_plans,
NULL,
rt_index,
inheritrtable,
((Plan *) lfirst(union_plans))->targetlist);
}
/*
@ -551,9 +551,18 @@ make_append(List *appendplans,
node->unionrtables = unionrtables;
node->inheritrelid = rt_index;
node->inheritrtable = inheritrtable;
node->plan.cost = 0.0;
node->plan.cost = 0;
node->plan.plan_rows = 0;
node->plan.plan_width = 0;
foreach(subnode, appendplans)
node->plan.cost += ((Plan *) lfirst(subnode))->cost;
{
Plan *subplan = (Plan *) lfirst(subnode);
node->plan.cost += subplan->cost;
node->plan.plan_rows += subplan->plan_rows;
if (node->plan.plan_width < subplan->plan_width)
node->plan.plan_width = subplan->plan_width;
}
node->plan.state = (EState *) NULL;
node->plan.targetlist = tlist;
node->plan.qual = NIL;