/*-------------------------------------------------------------------------
 *
 * paths.h
 *	  prototypes for various files in optimizer/path (were separate
 *	  header files)
 *
 *
 * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * $Id: paths.h,v 1.39 2000/01/26 05:58:20 momjian Exp $
 *
 *-------------------------------------------------------------------------
 */
#ifndef PATHS_H
#define PATHS_H

#include "nodes/relation.h"

/* default GEQO threshold (default value for geqo_rels) */
#define GEQO_RELS 11


/*
 * allpaths.c
 */
extern bool enable_geqo;
extern int	geqo_rels;

extern RelOptInfo *make_one_rel(Query *root, List *rels);

/*
 * indxpath.c
 *	  routines to generate index paths
 */
extern List *create_index_paths(Query *root, RelOptInfo *rel, List *indices,
				   List *restrictinfo_list,
				   List *joininfo_list);
extern Oid indexable_operator(Expr *clause, Oid opclass, Oid relam,
							  bool indexkey_on_left);
extern List *expand_indexqual_conditions(List *indexquals);

/*
 * tidpath.h
 *	  routines to generate tid paths
 */
extern List *create_tidscan_paths(Query *root, RelOptInfo *rel);

/*
 * joinpath.c
 *	   routines to create join paths
 */
extern void update_rels_pathlist_for_joins(Query *root, List *joinrels);


/*
 * orindxpath.c
 */
extern List *create_or_index_paths(Query *root, RelOptInfo *rel, List *clauses);

/*
 * pathkeys.c
 *	  utilities for matching and building path keys
 */
typedef enum
{
	PATHKEYS_EQUAL,				/* pathkeys are identical */
	PATHKEYS_BETTER1,			/* pathkey 1 is a superset of pathkey 2 */
	PATHKEYS_BETTER2,			/* vice versa */
	PATHKEYS_DIFFERENT			/* neither pathkey includes the other */
} PathKeysComparison;

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,
											bool indexpaths_only);
extern List *build_index_pathkeys(Query *root, RelOptInfo *rel,
								  IndexOptInfo *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,
											List *tlist);

/*
 * joinrels.c
 *	  routines to determine which relations to join
 */
extern List *make_rels_by_joins(Query *root, List *old_rels);
extern List *make_rels_by_clause_joins(Query *root, RelOptInfo *old_rel,
						  List *joininfo_list, Relids only_relids);
extern List *make_rels_by_clauseless_joins(RelOptInfo *old_rel,
							  List *inner_rels);
extern RelOptInfo *get_cheapest_complete_rel(List *join_rel_list);
extern bool nonoverlap_sets(List *s1, List *s2);
extern bool is_subset(List *s1, List *s2);

/*
 * prototypes for path/prune.c
 */
extern void merge_rels_with_same_relids(List *rel_list);
extern void rels_set_cheapest(Query *root, List *rel_list);
extern List *del_rels_all_bushy_inactive(List *old_rels);

#endif	 /* PATHS_H */