postgresql/src/include/optimizer/pathnode.h
Tom Lane 3ced8837db Simplify query_planner's API by having it return the top-level RelOptInfo.
Formerly, query_planner returned one or possibly two Paths for the topmost
join relation, so that grouping_planner didn't see the join RelOptInfo
(at least not directly; it didn't have any hesitation about examining
cheapest_path->parent, though).  However, correct selection of the Paths
involved a significant amount of coupling between query_planner and
grouping_planner, a problem which has gotten worse over time.  It seems
best to give up on this API choice and instead return the topmost
RelOptInfo explicitly.  Then grouping_planner can pull out the Paths it
wants from the rel's path list.  In this way we can remove all knowledge
of grouping behaviors from query_planner.

The only real benefit of the old way is that in the case of an empty
FROM clause, we never made any RelOptInfos at all, just a Path.  Now
we have to gin up a dummy RelOptInfo to represent the empty FROM clause.
That's not a very big deal though.

While at it, simplify query_planner's API a bit more by having the caller
set up root->tuple_fraction and root->limit_tuples, rather than passing
those values as separate parameters.  Since query_planner no longer does
anything with either value, requiring it to fill the PlannerInfo fields
seemed pretty arbitrary.

This patch just rearranges code; it doesn't (intentionally) change any
behaviors.  Followup patches will do more interesting things.
2013-08-05 15:01:09 -04:00

161 lines
5.6 KiB
C

/*-------------------------------------------------------------------------
*
* pathnode.h
* prototypes for pathnode.c, relnode.c.
*
*
* Portions Copyright (c) 1996-2013, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* src/include/optimizer/pathnode.h
*
*-------------------------------------------------------------------------
*/
#ifndef PATHNODE_H
#define PATHNODE_H
#include "nodes/relation.h"
/*
* prototypes for pathnode.c
*/
extern int compare_path_costs(Path *path1, Path *path2,
CostSelector criterion);
extern int compare_fractional_path_costs(Path *path1, Path *path2,
double fraction);
extern void set_cheapest(RelOptInfo *parent_rel);
extern void add_path(RelOptInfo *parent_rel, Path *new_path);
extern bool add_path_precheck(RelOptInfo *parent_rel,
Cost startup_cost, Cost total_cost,
List *pathkeys, Relids required_outer);
extern Path *create_seqscan_path(PlannerInfo *root, RelOptInfo *rel,
Relids required_outer);
extern IndexPath *create_index_path(PlannerInfo *root,
IndexOptInfo *index,
List *indexclauses,
List *indexclausecols,
List *indexorderbys,
List *indexorderbycols,
List *pathkeys,
ScanDirection indexscandir,
bool indexonly,
Relids required_outer,
double loop_count);
extern BitmapHeapPath *create_bitmap_heap_path(PlannerInfo *root,
RelOptInfo *rel,
Path *bitmapqual,
Relids required_outer,
double loop_count);
extern BitmapAndPath *create_bitmap_and_path(PlannerInfo *root,
RelOptInfo *rel,
List *bitmapquals);
extern BitmapOrPath *create_bitmap_or_path(PlannerInfo *root,
RelOptInfo *rel,
List *bitmapquals);
extern TidPath *create_tidscan_path(PlannerInfo *root, RelOptInfo *rel,
List *tidquals, Relids required_outer);
extern AppendPath *create_append_path(RelOptInfo *rel, List *subpaths,
Relids required_outer);
extern MergeAppendPath *create_merge_append_path(PlannerInfo *root,
RelOptInfo *rel,
List *subpaths,
List *pathkeys,
Relids required_outer);
extern ResultPath *create_result_path(List *quals);
extern MaterialPath *create_material_path(RelOptInfo *rel, Path *subpath);
extern UniquePath *create_unique_path(PlannerInfo *root, RelOptInfo *rel,
Path *subpath, SpecialJoinInfo *sjinfo);
extern Path *create_subqueryscan_path(PlannerInfo *root, RelOptInfo *rel,
List *pathkeys, Relids required_outer);
extern Path *create_functionscan_path(PlannerInfo *root, RelOptInfo *rel,
Relids required_outer);
extern Path *create_valuesscan_path(PlannerInfo *root, RelOptInfo *rel,
Relids required_outer);
extern Path *create_ctescan_path(PlannerInfo *root, RelOptInfo *rel,
Relids required_outer);
extern Path *create_worktablescan_path(PlannerInfo *root, RelOptInfo *rel,
Relids required_outer);
extern ForeignPath *create_foreignscan_path(PlannerInfo *root, RelOptInfo *rel,
double rows, Cost startup_cost, Cost total_cost,
List *pathkeys,
Relids required_outer,
List *fdw_private);
extern Relids calc_nestloop_required_outer(Path *outer_path, Path *inner_path);
extern Relids calc_non_nestloop_required_outer(Path *outer_path, Path *inner_path);
extern NestPath *create_nestloop_path(PlannerInfo *root,
RelOptInfo *joinrel,
JoinType jointype,
JoinCostWorkspace *workspace,
SpecialJoinInfo *sjinfo,
SemiAntiJoinFactors *semifactors,
Path *outer_path,
Path *inner_path,
List *restrict_clauses,
List *pathkeys,
Relids required_outer);
extern MergePath *create_mergejoin_path(PlannerInfo *root,
RelOptInfo *joinrel,
JoinType jointype,
JoinCostWorkspace *workspace,
SpecialJoinInfo *sjinfo,
Path *outer_path,
Path *inner_path,
List *restrict_clauses,
List *pathkeys,
Relids required_outer,
List *mergeclauses,
List *outersortkeys,
List *innersortkeys);
extern HashPath *create_hashjoin_path(PlannerInfo *root,
RelOptInfo *joinrel,
JoinType jointype,
JoinCostWorkspace *workspace,
SpecialJoinInfo *sjinfo,
SemiAntiJoinFactors *semifactors,
Path *outer_path,
Path *inner_path,
List *restrict_clauses,
Relids required_outer,
List *hashclauses);
extern Path *reparameterize_path(PlannerInfo *root, Path *path,
Relids required_outer,
double loop_count);
/*
* prototypes for relnode.c
*/
extern void setup_simple_rel_arrays(PlannerInfo *root);
extern RelOptInfo *build_simple_rel(PlannerInfo *root, int relid,
RelOptKind reloptkind);
extern RelOptInfo *find_base_rel(PlannerInfo *root, int relid);
extern RelOptInfo *find_join_rel(PlannerInfo *root, Relids relids);
extern RelOptInfo *build_join_rel(PlannerInfo *root,
Relids joinrelids,
RelOptInfo *outer_rel,
RelOptInfo *inner_rel,
SpecialJoinInfo *sjinfo,
List **restrictlist_ptr);
extern RelOptInfo *build_empty_join_rel(PlannerInfo *root);
extern AppendRelInfo *find_childrel_appendrelinfo(PlannerInfo *root,
RelOptInfo *rel);
extern ParamPathInfo *get_baserel_parampathinfo(PlannerInfo *root,
RelOptInfo *baserel,
Relids required_outer);
extern ParamPathInfo *get_joinrel_parampathinfo(PlannerInfo *root,
RelOptInfo *joinrel,
Path *outer_path,
Path *inner_path,
SpecialJoinInfo *sjinfo,
Relids required_outer,
List **restrict_clauses);
extern ParamPathInfo *get_appendrel_parampathinfo(RelOptInfo *appendrel,
Relids required_outer);
#endif /* PATHNODE_H */