src/include/optimizer/cost.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * cost.h
   4  *        prototypes for costsize.c and clausesel.c.
   5  *
   6  *
   7  * Portions Copyright (c) 1996-2008, 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
  33 /*
  34  * prototypes for costsize.c
  35  *        routines to compute costs and sizes
  36  */
  37
  38 /* parameter variables and flags */
  39 extern PGDLLIMPORT double seq_page_cost;
  40 extern PGDLLIMPORT double random_page_cost;
  41 extern PGDLLIMPORT double cpu_tuple_cost;
  42 extern PGDLLIMPORT double cpu_index_tuple_cost;
  43 extern PGDLLIMPORT double cpu_operator_cost;
  44 extern PGDLLIMPORT int effective_cache_size;
  45 extern Cost disable_cost;
  46 extern bool enable_seqscan;
  47 extern bool enable_indexscan;
  48 extern bool enable_bitmapscan;
  49 extern bool enable_tidscan;
  50 extern bool enable_sort;
  51 extern bool enable_hashagg;
  52 extern bool enable_nestloop;
  53 extern bool enable_mergejoin;
  54 extern bool enable_hashjoin;
  55 extern bool constraint_exclusion;
  56
  57 extern double clamp_row_est(double nrows);
  58 extern double index_pages_fetched(double tuples_fetched, BlockNumber pages,
  59                                         double index_pages, PlannerInfo *root);
  60 extern void cost_seqscan(Path *path, PlannerInfo *root, RelOptInfo *baserel);
  61 extern void cost_index(IndexPath *path, PlannerInfo *root, IndexOptInfo *index,
  62                    List *indexQuals, RelOptInfo *outer_rel);
  63 extern void cost_bitmap_heap_scan(Path *path, PlannerInfo *root, RelOptInfo *baserel,
  64                                           Path *bitmapqual, RelOptInfo *outer_rel);
  65 extern void cost_bitmap_and_node(BitmapAndPath *path, PlannerInfo *root);
  66 extern void cost_bitmap_or_node(BitmapOrPath *path, PlannerInfo *root);
  67 extern void cost_bitmap_tree_node(Path *path, Cost *cost, Selectivity *selec);
  68 extern void cost_tidscan(Path *path, PlannerInfo *root,
  69                          RelOptInfo *baserel, List *tidquals);
  70 extern void cost_subqueryscan(Path *path, RelOptInfo *baserel);
  71 extern void cost_functionscan(Path *path, PlannerInfo *root,
  72                                   RelOptInfo *baserel);
  73 extern void cost_valuesscan(Path *path, PlannerInfo *root,
  74                                 RelOptInfo *baserel);
  75 extern void cost_ctescan(Path *path, PlannerInfo *root, RelOptInfo *baserel);
  76 extern void cost_recursive_union(Plan *runion, Plan *nrterm, Plan *rterm);
  77 extern void cost_sort(Path *path, PlannerInfo *root,
  78                   List *pathkeys, Cost input_cost, double tuples, int width,
  79                   double limit_tuples);
  80 extern bool sort_exceeds_work_mem(Sort *sort);
  81 extern void cost_material(Path *path,
  82                           Cost input_cost, double tuples, int width);
  83 extern void cost_agg(Path *path, PlannerInfo *root,
  84                  AggStrategy aggstrategy, int numAggs,
  85                  int numGroupCols, double numGroups,
  86                  Cost input_startup_cost, Cost input_total_cost,
  87                  double input_tuples);
  88 extern void cost_group(Path *path, PlannerInfo *root,
  89                    int numGroupCols, double numGroups,
  90                    Cost input_startup_cost, Cost input_total_cost,
  91                    double input_tuples);
  92 extern void cost_nestloop(NestPath *path, PlannerInfo *root,
  93                                                   SpecialJoinInfo *sjinfo);
  94 extern void cost_mergejoin(MergePath *path, PlannerInfo *root,
  95                                                    SpecialJoinInfo *sjinfo);
  96 extern void cost_hashjoin(HashPath *path, PlannerInfo *root,
  97                                                   SpecialJoinInfo *sjinfo);
  98 extern void cost_subplan(PlannerInfo *root, SubPlan *subplan, Plan *plan);
  99 extern void cost_qual_eval(QualCost *cost, List *quals, PlannerInfo *root);
 100 extern void cost_qual_eval_node(QualCost *cost, Node *qual, PlannerInfo *root);
 101 extern void set_baserel_size_estimates(PlannerInfo *root, RelOptInfo *rel);
 102 extern void set_joinrel_size_estimates(PlannerInfo *root, RelOptInfo *rel,
 103                                                    RelOptInfo *outer_rel,
 104                                                    RelOptInfo *inner_rel,
 105                                                    SpecialJoinInfo *sjinfo,
 106                                                    List *restrictlist);
 107 extern void set_function_size_estimates(PlannerInfo *root, RelOptInfo *rel);
 108 extern void set_values_size_estimates(PlannerInfo *root, RelOptInfo *rel);
 109 extern void set_cte_size_estimates(PlannerInfo *root, RelOptInfo *rel,
 110                                                                    Plan *cteplan);
 111
 112 /*
 113  * prototypes for clausesel.c
 114  *        routines to compute clause selectivities
 115  */
 116 extern Selectivity clauselist_selectivity(PlannerInfo *root,
 117                                            List *clauses,
 118                                            int varRelid,
 119                                            JoinType jointype,
 120                                            SpecialJoinInfo *sjinfo);
 121 extern Selectivity clause_selectivity(PlannerInfo *root,
 122                                    Node *clause,
 123                                    int varRelid,
 124                                    JoinType jointype,
 125                                    SpecialJoinInfo *sjinfo);
 126
 127 #endif   /* COST_H */