src/include/optimizer/paths.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * paths.h
   4  *        prototypes for various files in optimizer/path (were separate
   5  *        header files)
   6  *
   7  *
   8  * Portions Copyright (c) 1996-2004, PostgreSQL Global Development Group
   9  * Portions Copyright (c) 1994, Regents of the University of California
  10  *
  11  * $PostgreSQL: pgsql/src/include/optimizer/paths.h,v 1.75 2004/08/29 05:06:57 momjian Exp $
  12  *
  13  *-------------------------------------------------------------------------
  14  */
  15 #ifndef PATHS_H
  16 #define PATHS_H
  17
  18 #include "nodes/relation.h"
  19
  20
  21 /*
  22  * allpaths.c
  23  */
  24 extern bool enable_geqo;
  25 extern int      geqo_threshold;
  26
  27 extern RelOptInfo *make_one_rel(Query *root);
  28 extern RelOptInfo *make_fromexpr_rel(Query *root, FromExpr *from);
  29
  30 #ifdef OPTIMIZER_DEBUG
  31 extern void debug_print_rel(Query *root, RelOptInfo *rel);
  32 #endif
  33
  34 /*
  35  * indxpath.c
  36  *        routines to generate index paths
  37  */
  38 extern void create_index_paths(Query *root, RelOptInfo *rel);
  39 extern Path *best_inner_indexscan(Query *root, RelOptInfo *rel,
  40                                          Relids outer_relids, JoinType jointype);
  41 extern List *group_clauses_by_indexkey_for_or(RelOptInfo *rel,
  42                                                                  IndexOptInfo *index,
  43                                                                  Expr *orsubclause);
  44 extern List *expand_indexqual_conditions(IndexOptInfo *index,
  45                                                         List *clausegroups);
  46 extern void check_partial_indexes(Query *root, RelOptInfo *rel);
  47 extern List *flatten_clausegroups_list(List *clausegroups);
  48 extern Expr *make_expr_from_indexclauses(List *indexclauses);
  49
  50 /*
  51  * orindxpath.c
  52  *        additional routines for indexable OR clauses
  53  */
  54 extern bool create_or_index_quals(Query *root, RelOptInfo *rel);
  55 extern void create_or_index_paths(Query *root, RelOptInfo *rel);
  56
  57 /*
  58  * tidpath.h
  59  *        routines to generate tid paths
  60  */
  61 extern void create_tidscan_paths(Query *root, RelOptInfo *rel);
  62
  63 /*
  64  * joinpath.c
  65  *         routines to create join paths
  66  */
  67 extern void add_paths_to_joinrel(Query *root, RelOptInfo *joinrel,
  68                                          RelOptInfo *outerrel,
  69                                          RelOptInfo *innerrel,
  70                                          JoinType jointype,
  71                                          List *restrictlist);
  72
  73 /*
  74  * joinrels.c
  75  *        routines to determine which relations to join
  76  */
  77 extern List *make_rels_by_joins(Query *root, int level, List **joinrels);
  78 extern RelOptInfo *make_jointree_rel(Query *root, Node *jtnode);
  79 extern RelOptInfo *make_join_rel(Query *root,
  80                           RelOptInfo *rel1, RelOptInfo *rel2,
  81                           JoinType jointype);
  82
  83 /*
  84  * pathkeys.c
  85  *        utilities for matching and building path keys
  86  */
  87 typedef enum
  88 {
  89         PATHKEYS_EQUAL,                         /* pathkeys are identical */
  90         PATHKEYS_BETTER1,                       /* pathkey 1 is a superset of pathkey 2 */
  91         PATHKEYS_BETTER2,                       /* vice versa */
  92         PATHKEYS_DIFFERENT                      /* neither pathkey includes the other */
  93 } PathKeysComparison;
  94
  95 extern void add_equijoined_keys(Query *root, RestrictInfo *restrictinfo);
  96 extern bool exprs_known_equal(Query *root, Node *item1, Node *item2);
  97 extern void generate_implied_equalities(Query *root);
  98 extern List *canonicalize_pathkeys(Query *root, List *pathkeys);
  99 extern PathKeysComparison compare_pathkeys(List *keys1, List *keys2);
 100 extern bool pathkeys_contained_in(List *keys1, List *keys2);
 101 extern PathKeysComparison compare_noncanonical_pathkeys(List *keys1,
 102                                                           List *keys2);
 103 extern bool noncanonical_pathkeys_contained_in(List *keys1, List *keys2);
 104 extern Path *get_cheapest_path_for_pathkeys(List *paths, List *pathkeys,
 105                                                            CostSelector cost_criterion);
 106 extern Path *get_cheapest_fractional_path_for_pathkeys(List *paths,
 107                                                                                   List *pathkeys,
 108                                                                                   double fraction);
 109 extern List *build_index_pathkeys(Query *root, RelOptInfo *rel,
 110                                          IndexOptInfo *index,
 111                                          ScanDirection scandir);
 112 extern List *build_subquery_pathkeys(Query *root, RelOptInfo *rel,
 113                                                 Query *subquery);
 114 extern List *build_join_pathkeys(Query *root,
 115                                         RelOptInfo *joinrel,
 116                                         List *outer_pathkeys);
 117 extern List *make_pathkeys_for_sortclauses(List *sortclauses,
 118                                                           List *tlist);
 119 extern void cache_mergeclause_pathkeys(Query *root,
 120                                                    RestrictInfo *restrictinfo);
 121 extern List *find_mergeclauses_for_pathkeys(Query *root,
 122                                                            List *pathkeys,
 123                                                            List *restrictinfos);
 124 extern List *make_pathkeys_for_mergeclauses(Query *root,
 125                                                            List *mergeclauses,
 126                                                            RelOptInfo *rel);
 127 extern int pathkeys_useful_for_merging(Query *root,
 128                                                         RelOptInfo *rel,
 129                                                         List *pathkeys);
 130 extern int      pathkeys_useful_for_ordering(Query *root, List *pathkeys);
 131 extern List *truncate_useless_pathkeys(Query *root,
 132                                                   RelOptInfo *rel,
 133                                                   List *pathkeys);
 134
 135 #endif   /* PATHS_H */