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

   1 /*-------------------------------------------------------------------------
   2  *
   3  * cost.h
   4  *        prototypes for costsize.c and clausesel.c.
   5  *
   6  *
   7  * Portions Copyright (c) 1996-2011, PostgreSQL Global Development Group
   8  * Portions Copyright (c) 1994, Regents of the University of California
   9  *
  10  * src/include/optimizer/cost.h
  11  *
  12  *-------------------------------------------------------------------------
  13  */
  14 #ifndef COST_H
  15 #define COST_H
  16
  17 #include "nodes/plannodes.h"
  18 #include "nodes/relation.h"
  19
  20
  21 /* defaults for costsize.c's Cost parameters */
  22 /* NB: cost-estimation code should use the variables, not these constants! */
  23 /* If you change these, update backend/utils/misc/postgresql.sample.conf */
  24 #define DEFAULT_SEQ_PAGE_COST  1.0
  25 #define DEFAULT_RANDOM_PAGE_COST  4.0
  26 #define DEFAULT_CPU_TUPLE_COST  0.01
  27 #define DEFAULT_CPU_INDEX_TUPLE_COST 0.005
  28 #define DEFAULT_CPU_OPERATOR_COST  0.0025
  29
  30 #define DEFAULT_EFFECTIVE_CACHE_SIZE  16384             /* measured in pages */
  31
  32 typedef enum
  33 {
  34         CONSTRAINT_EXCLUSION_OFF,       /* do not use c_e */
  35         CONSTRAINT_EXCLUSION_ON,        /* apply c_e to all rels */
  36         CONSTRAINT_EXCLUSION_PARTITION          /* apply c_e to otherrels only */
  37 } ConstraintExclusionType;
  38
  39
  40 /*
  41  * prototypes for costsize.c
  42  *        routines to compute costs and sizes
  43  */
  44
  45 /* parameter variables and flags */
  46 extern PGDLLIMPORT double seq_page_cost;
  47 extern PGDLLIMPORT double random_page_cost;
  48 extern PGDLLIMPORT double cpu_tuple_cost;
  49 extern PGDLLIMPORT double cpu_index_tuple_cost;
  50 extern PGDLLIMPORT double cpu_operator_cost;
  51 extern PGDLLIMPORT int effective_cache_size;
  52 extern Cost disable_cost;
  53 extern bool enable_seqscan;
  54 extern bool enable_indexscan;
  55 extern bool enable_bitmapscan;
  56 extern bool enable_tidscan;
  57 extern bool enable_sort;
  58 extern bool enable_hashagg;
  59 extern bool enable_nestloop;
  60 extern bool enable_material;
  61 extern bool enable_mergejoin;
  62 extern bool enable_hashjoin;
  63 extern int      constraint_exclusion;
  64
  65 extern double clamp_row_est(double nrows);
  66 extern double index_pages_fetched(double tuples_fetched, BlockNumber pages,
  67                                         double index_pages, PlannerInfo *root);
  68 extern void cost_seqscan(Path *path, PlannerInfo *root, RelOptInfo *baserel);
  69 extern void cost_index(IndexPath *path, PlannerInfo *root, IndexOptInfo *index,
  70                    List *indexQuals, List *indexOrderBys, RelOptInfo *outer_rel);
  71 extern void cost_bitmap_heap_scan(Path *path, PlannerInfo *root, RelOptInfo *baserel,
  72                                           Path *bitmapqual, RelOptInfo *outer_rel);
  73 extern void cost_bitmap_and_node(BitmapAndPath *path, PlannerInfo *root);
  74 extern void cost_bitmap_or_node(BitmapOrPath *path, PlannerInfo *root);
  75 extern void cost_bitmap_tree_node(Path *path, Cost *cost, Selectivity *selec);
  76 extern void cost_tidscan(Path *path, PlannerInfo *root,
  77                          RelOptInfo *baserel, List *tidquals);
  78 extern void cost_subqueryscan(Path *path, RelOptInfo *baserel);
  79 extern void cost_functionscan(Path *path, PlannerInfo *root,
  80                                   RelOptInfo *baserel);
  81 extern void cost_valuesscan(Path *path, PlannerInfo *root,
  82                                 RelOptInfo *baserel);
  83 extern void cost_ctescan(Path *path, PlannerInfo *root, RelOptInfo *baserel);
  84 extern void cost_recursive_union(Plan *runion, Plan *nrterm, Plan *rterm);
  85 extern void cost_sort(Path *path, PlannerInfo *root,
  86                   List *pathkeys, Cost input_cost, double tuples, int width,
  87                   Cost comparison_cost, int sort_mem,
  88                   double limit_tuples);
  89 extern void cost_merge_append(Path *path, PlannerInfo *root,
  90                                   List *pathkeys, int n_streams,
  91                                   Cost input_startup_cost, Cost input_total_cost,
  92                                   double tuples);
  93 extern void cost_material(Path *path,
  94                           Cost input_startup_cost, Cost input_total_cost,
  95                           double tuples, int width);
  96 extern void cost_agg(Path *path, PlannerInfo *root,
  97                  AggStrategy aggstrategy, int numAggs,
  98                  int numGroupCols, double numGroups,
  99                  Cost input_startup_cost, Cost input_total_cost,
 100                  double input_tuples);
 101 extern void cost_windowagg(Path *path, PlannerInfo *root,
 102                            int numWindowFuncs, int numPartCols, int numOrderCols,
 103                            Cost input_startup_cost, Cost input_total_cost,
 104                            double input_tuples);
 105 extern void cost_group(Path *path, PlannerInfo *root,
 106                    int numGroupCols, double numGroups,
 107                    Cost input_startup_cost, Cost input_total_cost,
 108                    double input_tuples);
 109 extern void cost_nestloop(NestPath *path, PlannerInfo *root,
 110                           SpecialJoinInfo *sjinfo);
 111 extern void cost_mergejoin(MergePath *path, PlannerInfo *root,
 112                            SpecialJoinInfo *sjinfo);
 113 extern void cost_hashjoin(HashPath *path, PlannerInfo *root,
 114                           SpecialJoinInfo *sjinfo);
 115 extern void cost_subplan(PlannerInfo *root, SubPlan *subplan, Plan *plan);
 116 extern void cost_qual_eval(QualCost *cost, List *quals, PlannerInfo *root);
 117 extern void cost_qual_eval_node(QualCost *cost, Node *qual, PlannerInfo *root);
 118 extern void set_baserel_size_estimates(PlannerInfo *root, RelOptInfo *rel);
 119 extern void set_joinrel_size_estimates(PlannerInfo *root, RelOptInfo *rel,
 120                                                    RelOptInfo *outer_rel,
 121                                                    RelOptInfo *inner_rel,
 122                                                    SpecialJoinInfo *sjinfo,
 123                                                    List *restrictlist);
 124 extern void set_subquery_size_estimates(PlannerInfo *root, RelOptInfo *rel,
 125                                                         PlannerInfo *subroot);
 126 extern void set_function_size_estimates(PlannerInfo *root, RelOptInfo *rel);
 127 extern void set_values_size_estimates(PlannerInfo *root, RelOptInfo *rel);
 128 extern void set_cte_size_estimates(PlannerInfo *root, RelOptInfo *rel,
 129                                            Plan *cteplan);
 130
 131 /*
 132  * prototypes for clausesel.c
 133  *        routines to compute clause selectivities
 134  */
 135 extern Selectivity clauselist_selectivity(PlannerInfo *root,
 136                                            List *clauses,
 137                                            int varRelid,
 138                                            JoinType jointype,
 139                                            SpecialJoinInfo *sjinfo);
 140 extern Selectivity clause_selectivity(PlannerInfo *root,
 141                                    Node *clause,
 142                                    int varRelid,
 143                                    JoinType jointype,
 144                                    SpecialJoinInfo *sjinfo);
 145
 146 #endif   /* COST_H */