src/include/optimizer/cost.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * cost.h
   4  *        prototypes for costsize.c and clausesel.c.
   5  *
   6  *
   7  * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
   8  * Portions Copyright (c) 1994, Regents of the University of California
   9  *
  10  * $PostgreSQL$
  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_mergejoin;
  61 extern bool enable_hashjoin;
  62 extern int      constraint_exclusion;
  63
  64 extern double clamp_row_est(double nrows);
  65 extern double index_pages_fetched(double tuples_fetched, BlockNumber pages,
  66                                         double index_pages, PlannerInfo *root);
  67 extern void cost_seqscan(Path *path, PlannerInfo *root, RelOptInfo *baserel);
  68 extern void cost_index(IndexPath *path, PlannerInfo *root, IndexOptInfo *index,
  69                    List *indexQuals, RelOptInfo *outer_rel);
  70 extern void cost_bitmap_heap_scan(Path *path, PlannerInfo *root, RelOptInfo *baserel,
  71                                           Path *bitmapqual, RelOptInfo *outer_rel);
  72 extern void cost_bitmap_and_node(BitmapAndPath *path, PlannerInfo *root);
  73 extern void cost_bitmap_or_node(BitmapOrPath *path, PlannerInfo *root);
  74 extern void cost_bitmap_tree_node(Path *path, Cost *cost, Selectivity *selec);
  75 extern void cost_tidscan(Path *path, PlannerInfo *root,
  76                          RelOptInfo *baserel, List *tidquals);
  77 extern void cost_subqueryscan(Path *path, RelOptInfo *baserel);
  78 extern void cost_functionscan(Path *path, PlannerInfo *root,
  79                                   RelOptInfo *baserel);
  80 extern void cost_valuesscan(Path *path, PlannerInfo *root,
  81                                 RelOptInfo *baserel);
  82 extern void cost_ctescan(Path *path, PlannerInfo *root, RelOptInfo *baserel);
  83 extern void cost_recursive_union(Plan *runion, Plan *nrterm, Plan *rterm);
  84 extern void cost_sort(Path *path, PlannerInfo *root,
  85                   List *pathkeys, Cost input_cost, double tuples, int width,
  86                   double limit_tuples);
  87 extern bool sort_exceeds_work_mem(Sort *sort);
  88 extern void cost_material(Path *path,
  89                           Cost input_cost, double tuples, int width);
  90 extern void cost_agg(Path *path, PlannerInfo *root,
  91                  AggStrategy aggstrategy, int numAggs,
  92                  int numGroupCols, double numGroups,
  93                  Cost input_startup_cost, Cost input_total_cost,
  94                  double input_tuples);
  95 extern void cost_windowagg(Path *path, PlannerInfo *root,
  96                            int numWindowFuncs, int numPartCols, int numOrderCols,
  97                            Cost input_startup_cost, Cost input_total_cost,
  98                            double input_tuples);
  99 extern void cost_group(Path *path, PlannerInfo *root,
 100                    int numGroupCols, double numGroups,
 101                    Cost input_startup_cost, Cost input_total_cost,
 102                    double input_tuples);
 103 extern void cost_nestloop(NestPath *path, PlannerInfo *root,
 104                           SpecialJoinInfo *sjinfo);
 105 extern void cost_mergejoin(MergePath *path, PlannerInfo *root,
 106                            SpecialJoinInfo *sjinfo);
 107 extern void cost_hashjoin(HashPath *path, PlannerInfo *root,
 108                           SpecialJoinInfo *sjinfo);
 109 extern void cost_subplan(PlannerInfo *root, SubPlan *subplan, Plan *plan);
 110 extern void cost_qual_eval(QualCost *cost, List *quals, PlannerInfo *root);
 111 extern void cost_qual_eval_node(QualCost *cost, Node *qual, PlannerInfo *root);
 112 extern void set_baserel_size_estimates(PlannerInfo *root, RelOptInfo *rel);
 113 extern void set_joinrel_size_estimates(PlannerInfo *root, RelOptInfo *rel,
 114                                                    RelOptInfo *outer_rel,
 115                                                    RelOptInfo *inner_rel,
 116                                                    SpecialJoinInfo *sjinfo,
 117                                                    List *restrictlist);
 118 extern void set_function_size_estimates(PlannerInfo *root, RelOptInfo *rel);
 119 extern void set_values_size_estimates(PlannerInfo *root, RelOptInfo *rel);
 120 extern void set_cte_size_estimates(PlannerInfo *root, RelOptInfo *rel,
 121                                            Plan *cteplan);
 122
 123 /*
 124  * prototypes for clausesel.c
 125  *        routines to compute clause selectivities
 126  */
 127 extern Selectivity clauselist_selectivity(PlannerInfo *root,
 128                                            List *clauses,
 129                                            int varRelid,
 130                                            JoinType jointype,
 131                                            SpecialJoinInfo *sjinfo);
 132 extern Selectivity clause_selectivity(PlannerInfo *root,
 133                                    Node *clause,
 134                                    int varRelid,
 135                                    JoinType jointype,
 136                                    SpecialJoinInfo *sjinfo);
 137
 138 #endif   /* COST_H */