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Major revision of sort-node handling: push knowledge of query

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sort order down into planner, instead of handling it only at the very top
level of the planner.  This fixes many things.  An explicit sort is now
avoided if there is a cheaper alternative (typically an indexscan) not
only for ORDER BY, but also for the internal sort of GROUP BY.  It works
even when there is no other reason (such as a WHERE condition) to consider
the indexscan.  It works for indexes on functions.  It works for indexes
on functions, backwards.  It's just so cool...

CAUTION: I have changed the representation of SortClause nodes, therefore
THIS UPDATE BREAKS STORED RULES.  You will need to initdb.
This commit is contained in:
Tom Lane
1999-08-21 03:49:17 +00:00
parent 5588c559e6
commit db436adf76
33 changed files with 967 additions and 1002 deletions
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8
src/include/optimizer/paths.h
View File

@@ -7,7 +7,7 @@
*
* Copyright (c) 1994, Regents of the University of California
*
* $Id: paths.h,v 1.34 1999/08/16 02:17:45 tgl Exp $
* $Id: paths.h,v 1.35 1999/08/21 03:49:15 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -56,11 +56,15 @@ typedef enum
extern PathKeysComparison compare_pathkeys(List *keys1, List *keys2);
extern bool pathkeys_contained_in(List *keys1, List *keys2);
extern Path *get_cheapest_path_for_pathkeys(List *paths, List *pathkeys);
extern Path *get_cheapest_path_for_pathkeys(List *paths, List *pathkeys,
bool indexpaths_only);
extern List *build_index_pathkeys(Query *root, RelOptInfo *rel,
RelOptInfo *index);
extern List *build_join_pathkeys(List *outer_pathkeys,
List *join_rel_tlist, List *joinclauses);
extern bool commute_pathkeys(List *pathkeys);
extern List *make_pathkeys_for_sortclauses(List *sortclauses,
List *tlist);
extern List *find_mergeclauses_for_pathkeys(List *pathkeys,
List *restrictinfos);
extern List *make_pathkeys_for_mergeclauses(List *mergeclauses,

9
src/include/optimizer/planmain.h
View File

@@ -6,7 +6,7 @@
*
* Copyright (c) 1994, Regents of the University of California
*
* $Id: planmain.h,v 1.30 1999/08/09 00:56:04 tgl Exp $
* $Id: planmain.h,v 1.31 1999/08/21 03:49:15 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -33,7 +33,7 @@ extern Sort *make_sort(List *tlist, Oid nonameid, Plan *lefttree,
int keycount);
extern Agg *make_agg(List *tlist, Plan *lefttree);
extern Group *make_group(List *tlist, bool tuplePerGroup, int ngrp,
AttrNumber *grpColIdx, Sort *lefttree);
AttrNumber *grpColIdx, Plan *lefttree);
extern Unique *make_unique(List *tlist, Plan *lefttree, char *uniqueAttr);
/*
@@ -54,9 +54,14 @@ extern void replace_tlist_with_subplan_refs(List *tlist,
Index subvarno,
List *subplanTargetList);
extern bool set_agg_tlist_references(Agg *aggNode);
extern List *pull_agg_clause(Node *clause);
extern void check_having_for_ungrouped_vars(Node *clause,
List *groupClause,
List *targetList);
/*
* prep/prepkeyset.c
*/
extern void transformKeySetQuery(Query *origNode);
#endif /* PLANMAIN_H */

11
src/include/optimizer/tlist.h
View File

@@ -6,7 +6,7 @@
*
* Copyright (c) 1994, Regents of the University of California
*
* $Id: tlist.h,v 1.20 1999/08/16 02:17:45 tgl Exp $
* $Id: tlist.h,v 1.21 1999/08/21 03:49:15 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -21,16 +21,17 @@ extern void add_var_to_tlist(RelOptInfo *rel, Var *var);
extern TargetEntry *create_tl_element(Var *var, int resdomno);
extern List *get_actual_tlist(List *tlist);
extern Resdom *tlist_member(Var *var, List *tlist);
extern Resdom *tlist_resdom(List *tlist, Resdom *resnode);
extern TargetEntry *match_varid(Var *test_var, List *tlist);
extern List *new_unsorted_tlist(List *targetlist);
extern List *copy_vars(List *target, List *source);
extern List *flatten_tlist(List *tlist);
extern List *flatten_tlist_vars(List *full_tlist,
List *flat_tlist);
extern List *add_to_flat_tlist(List *tlist, List *vars);
extern List *unflatten_tlist(List *full_tlist,
List *flat_tlist);
extern Var *get_expr(TargetEntry *tle);
extern Var *get_groupclause_expr(GroupClause *groupClause, List *targetList);
extern Node *get_sortgroupclause_expr(SortClause *sortClause,
List *targetList);
#endif /* TLIST_H */