database/postgres
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Implement choice between hash-based and sort-based grouping for doing

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DISTINCT processing on the output of an IN sub-select.
This commit is contained in:
Tom Lane
2003-01-22 00:07:00 +00:00
parent a4482f4c4c
commit e2114817c7
2 changed files with 105 additions and 12 deletions
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36
src/backend/optimizer/plan/createplan.c
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@ -10,12 +10,13 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/plan/createplan.c,v 1.132 2003/01/20 18:54:52 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/plan/createplan.c,v 1.133 2003/01/22 00:07:00 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include <limits.h>
#include "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
@ -418,6 +419,7 @@ create_unique_plan(Query *root, UniquePath *best_path)
Plan *plan;
Plan *subplan;
List *sub_targetlist;
List *my_tlist;
List *l;
subplan = create_plan(root, best_path->subpath);
@ -474,21 +476,39 @@ create_unique_plan(Query *root, UniquePath *best_path)
subplan->targetlist = newtlist;
}
my_tlist = new_unsorted_tlist(subplan->targetlist);
if (best_path->use_hash)
{
elog(ERROR, "create_unique_plan: hash case not implemented yet");
plan = NULL;
int numGroupCols = length(my_tlist);
long numGroups;
AttrNumber *groupColIdx;
int i;
numGroups = (long) Min(best_path->rows, (double) LONG_MAX);
groupColIdx = (AttrNumber *) palloc(numGroupCols * sizeof(AttrNumber));
for (i = 0; i < numGroupCols; i++)
groupColIdx[i] = i+1;
plan = (Plan *) make_agg(root,
my_tlist,
NIL,
AGG_HASHED,
numGroupCols,
groupColIdx,
numGroups,
0,
subplan);
}
else
{
List *sort_tlist;
List *sortList;
sort_tlist = new_unsorted_tlist(subplan->targetlist);
sortList = addAllTargetsToSortList(NIL, sort_tlist);
plan = (Plan *) make_sort_from_sortclauses(root, sort_tlist,
sortList = addAllTargetsToSortList(NIL, my_tlist);
plan = (Plan *) make_sort_from_sortclauses(root, my_tlist,
subplan, sortList);
plan = (Plan *) make_unique(sort_tlist, plan, sortList);
plan = (Plan *) make_unique(my_tlist, plan, sortList);
}
plan->plan_rows = best_path->rows;