granicus.if.org Git - postgresql/blob - src/include/optimizer/paths.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * paths.h
   4  *        prototypes for various files in optimizer/path
   5  *
   6  *
   7  * Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
   8  * Portions Copyright (c) 1994, Regents of the University of California
   9  *
  10  * $PostgreSQL: pgsql/src/include/optimizer/paths.h,v 1.110 2010/01/02 16:58:07 momjian Exp $
  11  *
  12  *-------------------------------------------------------------------------
  13  */
  14 #ifndef PATHS_H
  15 #define PATHS_H
  16
  17 #include "nodes/relation.h"
  18
  19
  20 /*
  21  * allpaths.c
  22  */
  23 extern bool enable_geqo;
  24 extern int      geqo_threshold;
  25
  26 /* Hook for plugins to replace standard_join_search() */
  27 typedef RelOptInfo *(*join_search_hook_type) (PlannerInfo *root,
  28                                                                                                                   int levels_needed,
  29                                                                                                                   List *initial_rels);
  30 extern PGDLLIMPORT join_search_hook_type join_search_hook;
  31
  32
  33 extern RelOptInfo *make_one_rel(PlannerInfo *root, List *joinlist);
  34 extern RelOptInfo *standard_join_search(PlannerInfo *root, int levels_needed,
  35                                          List *initial_rels);
  36
  37 #ifdef OPTIMIZER_DEBUG
  38 extern void debug_print_rel(PlannerInfo *root, RelOptInfo *rel);
  39 #endif
  40
  41 /*
  42  * indxpath.c
  43  *        routines to generate index paths
  44  */
  45 typedef enum
  46 {
  47         /* Whether to use ScalarArrayOpExpr to build index qualifications */
  48         SAOP_FORBID,                            /* Do not use ScalarArrayOpExpr */
  49         SAOP_ALLOW,                                     /* OK to use ScalarArrayOpExpr */
  50         SAOP_REQUIRE                            /* Require ScalarArrayOpExpr */
  51 } SaOpControl;
  52
  53 extern void create_index_paths(PlannerInfo *root, RelOptInfo *rel);
  54 extern List *generate_bitmap_or_paths(PlannerInfo *root, RelOptInfo *rel,
  55                                                  List *clauses, List *outer_clauses,
  56                                                  RelOptInfo *outer_rel);
  57 extern void best_inner_indexscan(PlannerInfo *root, RelOptInfo *rel,
  58                                          RelOptInfo *outer_rel, JoinType jointype,
  59                                          Path **cheapest_startup, Path **cheapest_total);
  60 extern bool relation_has_unique_index_for(PlannerInfo *root, RelOptInfo *rel,
  61                                                           List *restrictlist);
  62 extern List *group_clauses_by_indexkey(IndexOptInfo *index,
  63                                                   List *clauses, List *outer_clauses,
  64                                                   Relids outer_relids,
  65                                                   SaOpControl saop_control,
  66                                                   bool *found_clause);
  67 extern bool eclass_matches_any_index(EquivalenceClass *ec,
  68                                                  EquivalenceMember *em,
  69                                                  RelOptInfo *rel);
  70 extern bool match_index_to_operand(Node *operand, int indexcol,
  71                                            IndexOptInfo *index);
  72 extern List *expand_indexqual_conditions(IndexOptInfo *index,
  73                                                         List *clausegroups);
  74 extern void check_partial_indexes(PlannerInfo *root, RelOptInfo *rel);
  75 extern List *flatten_clausegroups_list(List *clausegroups);
  76
  77 /*
  78  * orindxpath.c
  79  *        additional routines for indexable OR clauses
  80  */
  81 extern bool create_or_index_quals(PlannerInfo *root, RelOptInfo *rel);
  82
  83 /*
  84  * tidpath.h
  85  *        routines to generate tid paths
  86  */
  87 extern void create_tidscan_paths(PlannerInfo *root, RelOptInfo *rel);
  88
  89 /*
  90  * joinpath.c
  91  *         routines to create join paths
  92  */
  93 extern void add_paths_to_joinrel(PlannerInfo *root, RelOptInfo *joinrel,
  94                                          RelOptInfo *outerrel, RelOptInfo *innerrel,
  95                                          JoinType jointype, SpecialJoinInfo *sjinfo,
  96                                          List *restrictlist);
  97
  98 /*
  99  * joinrels.c
 100  *        routines to determine which relations to join
 101  */
 102 extern void join_search_one_level(PlannerInfo *root, int level);
 103 extern RelOptInfo *make_join_rel(PlannerInfo *root,
 104                           RelOptInfo *rel1, RelOptInfo *rel2);
 105 extern bool have_join_order_restriction(PlannerInfo *root,
 106                                                         RelOptInfo *rel1, RelOptInfo *rel2);
 107
 108 /*
 109  * equivclass.c
 110  *        routines for managing EquivalenceClasses
 111  */
 112 extern bool process_equivalence(PlannerInfo *root, RestrictInfo *restrictinfo,
 113                                         bool below_outer_join);
 114 extern void reconsider_outer_join_clauses(PlannerInfo *root);
 115 extern EquivalenceClass *get_eclass_for_sort_expr(PlannerInfo *root,
 116                                                  Expr *expr,
 117                                                  Oid expr_datatype,
 118                                                  List *opfamilies,
 119                                                  Index sortref);
 120 extern void generate_base_implied_equalities(PlannerInfo *root);
 121 extern List *generate_join_implied_equalities(PlannerInfo *root,
 122                                                                  RelOptInfo *joinrel,
 123                                                                  RelOptInfo *outer_rel,
 124                                                                  RelOptInfo *inner_rel);
 125 extern bool exprs_known_equal(PlannerInfo *root, Node *item1, Node *item2);
 126 extern void add_child_rel_equivalences(PlannerInfo *root,
 127                                                    AppendRelInfo *appinfo,
 128                                                    RelOptInfo *parent_rel,
 129                                                    RelOptInfo *child_rel);
 130 extern void mutate_eclass_expressions(PlannerInfo *root,
 131                                                   Node *(*mutator) (),
 132                                                   void *context);
 133 extern List *find_eclass_clauses_for_index_join(PlannerInfo *root,
 134                                                                    RelOptInfo *rel,
 135                                                                    Relids outer_relids);
 136 extern bool have_relevant_eclass_joinclause(PlannerInfo *root,
 137                                                                 RelOptInfo *rel1, RelOptInfo *rel2);
 138 extern bool has_relevant_eclass_joinclause(PlannerInfo *root,
 139                                                            RelOptInfo *rel1);
 140 extern bool eclass_useful_for_merging(EquivalenceClass *eclass,
 141                                                   RelOptInfo *rel);
 142
 143 /*
 144  * pathkeys.c
 145  *        utilities for matching and building path keys
 146  */
 147 typedef enum
 148 {
 149         PATHKEYS_EQUAL,                         /* pathkeys are identical */
 150         PATHKEYS_BETTER1,                       /* pathkey 1 is a superset of pathkey 2 */
 151         PATHKEYS_BETTER2,                       /* vice versa */
 152         PATHKEYS_DIFFERENT                      /* neither pathkey includes the other */
 153 } PathKeysComparison;
 154
 155 extern List *canonicalize_pathkeys(PlannerInfo *root, List *pathkeys);
 156 extern PathKeysComparison compare_pathkeys(List *keys1, List *keys2);
 157 extern bool pathkeys_contained_in(List *keys1, List *keys2);
 158 extern Path *get_cheapest_path_for_pathkeys(List *paths, List *pathkeys,
 159                                                            CostSelector cost_criterion);
 160 extern Path *get_cheapest_fractional_path_for_pathkeys(List *paths,
 161                                                                                   List *pathkeys,
 162                                                                                   double fraction);
 163 extern List *build_index_pathkeys(PlannerInfo *root, IndexOptInfo *index,
 164                                          ScanDirection scandir);
 165 extern List *convert_subquery_pathkeys(PlannerInfo *root, RelOptInfo *rel,
 166                                                   List *subquery_pathkeys);
 167 extern List *build_join_pathkeys(PlannerInfo *root,
 168                                         RelOptInfo *joinrel,
 169                                         JoinType jointype,
 170                                         List *outer_pathkeys);
 171 extern List *make_pathkeys_for_sortclauses(PlannerInfo *root,
 172                                                           List *sortclauses,
 173                                                           List *tlist,
 174                                                           bool canonicalize);
 175 extern void cache_mergeclause_eclasses(PlannerInfo *root,
 176                                                    RestrictInfo *restrictinfo);
 177 extern List *find_mergeclauses_for_pathkeys(PlannerInfo *root,
 178                                                            List *pathkeys,
 179                                                            bool outer_keys,
 180                                                            List *restrictinfos);
 181 extern List *select_outer_pathkeys_for_merge(PlannerInfo *root,
 182                                                                 List *mergeclauses,
 183                                                                 RelOptInfo *joinrel);
 184 extern List *make_inner_pathkeys_for_merge(PlannerInfo *root,
 185                                                           List *mergeclauses,
 186                                                           List *outer_pathkeys);
 187 extern int pathkeys_useful_for_merging(PlannerInfo *root,
 188                                                         RelOptInfo *rel,
 189                                                         List *pathkeys);
 190 extern int      pathkeys_useful_for_ordering(PlannerInfo *root, List *pathkeys);
 191 extern List *truncate_useless_pathkeys(PlannerInfo *root,
 192                                                   RelOptInfo *rel,
 193                                                   List *pathkeys);
 194 extern bool has_useful_pathkeys(PlannerInfo *root, RelOptInfo *rel);
 195
 196 #endif   /* PATHS_H */