cost.h

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/*-------------------------------------------------------------------------
 *
 * cost.h
 *    prototypes for costsize.c and clausesel.c.
 *
 *
 * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * src/include/optimizer/cost.h
 *
 *-------------------------------------------------------------------------
 */
#ifndef COST_H
#define COST_H
 
#include "nodes/pathnodes.h"
#include "nodes/plannodes.h"
 
 
/* defaults for costsize.c's Cost parameters */
/* NB: cost-estimation code should use the variables, not these constants! */
/* If you change these, update backend/utils/misc/postgresql.conf.sample */
#define DEFAULT_SEQ_PAGE_COST  1.0
#define DEFAULT_RANDOM_PAGE_COST  4.0
#define DEFAULT_CPU_TUPLE_COST  0.01
#define DEFAULT_CPU_INDEX_TUPLE_COST 0.005
#define DEFAULT_CPU_OPERATOR_COST  0.0025
#define DEFAULT_PARALLEL_TUPLE_COST 0.1
#define DEFAULT_PARALLEL_SETUP_COST  1000.0
 
/* defaults for non-Cost parameters */
#define DEFAULT_RECURSIVE_WORKTABLE_FACTOR  10.0
#define DEFAULT_EFFECTIVE_CACHE_SIZE  524288    /* measured in pages */
 
typedef enum
{
    CONSTRAINT_EXCLUSION_OFF,   /* do not use c_e */
    CONSTRAINT_EXCLUSION_ON,    /* apply c_e to all rels */
    CONSTRAINT_EXCLUSION_PARTITION, /* apply c_e to otherrels only */
}           ConstraintExclusionType;
 
 
/*
 * prototypes for costsize.c
 *    routines to compute costs and sizes
 */
 
/* parameter variables and flags (see also optimizer.h) */
extern PGDLLIMPORT Cost disable_cost;
extern PGDLLIMPORT int max_parallel_workers_per_gather;
extern PGDLLIMPORT bool enable_seqscan;
extern PGDLLIMPORT bool enable_indexscan;
extern PGDLLIMPORT bool enable_indexonlyscan;
extern PGDLLIMPORT bool enable_bitmapscan;
extern PGDLLIMPORT bool enable_tidscan;
extern PGDLLIMPORT bool enable_sort;
extern PGDLLIMPORT bool enable_incremental_sort;
extern PGDLLIMPORT bool enable_hashagg;
extern PGDLLIMPORT bool enable_groupagg;
extern PGDLLIMPORT bool enable_nestloop;
extern PGDLLIMPORT bool enable_material;
extern PGDLLIMPORT bool enable_memoize;
extern PGDLLIMPORT bool enable_mergejoin;
extern PGDLLIMPORT bool enable_hashjoin;
extern PGDLLIMPORT bool enable_gathermerge;
extern PGDLLIMPORT bool enable_partitionwise_join;
extern PGDLLIMPORT bool enable_partitionwise_aggregate;
extern PGDLLIMPORT bool enable_parallel_append;
extern PGDLLIMPORT bool enable_parallel_hash;
extern PGDLLIMPORT bool enable_partition_pruning;
extern PGDLLIMPORT bool enable_presorted_aggregate;
extern PGDLLIMPORT bool enable_async_append;
extern PGDLLIMPORT int constraint_exclusion;
 
extern double index_pages_fetched(double tuples_fetched, BlockNumber pages,
                                  double index_pages, PlannerInfo *root);
extern void cost_seqscan(Path *path, PlannerInfo *root, RelOptInfo *baserel,
                         ParamPathInfo *param_info);
extern void cost_samplescan(Path *path, PlannerInfo *root, RelOptInfo *baserel,
                            ParamPathInfo *param_info);
extern void cost_index(IndexPath *path, PlannerInfo *root,
                       double loop_count, bool partial_path);
extern void cost_bitmap_heap_scan(Path *path, PlannerInfo *root, RelOptInfo *baserel,
                                  ParamPathInfo *param_info,
                                  Path *bitmapqual, double loop_count);
extern void cost_bitmap_and_node(BitmapAndPath *path, PlannerInfo *root);
extern void cost_bitmap_or_node(BitmapOrPath *path, PlannerInfo *root);
extern void cost_bitmap_tree_node(Path *path, Cost *cost, Selectivity *selec);
extern void cost_tidscan(Path *path, PlannerInfo *root,
                         RelOptInfo *baserel, List *tidquals, ParamPathInfo *param_info);
extern void cost_tidrangescan(Path *path, PlannerInfo *root,
                              RelOptInfo *baserel, List *tidrangequals,
                              ParamPathInfo *param_info);
extern void cost_subqueryscan(SubqueryScanPath *path, PlannerInfo *root,
                              RelOptInfo *baserel, ParamPathInfo *param_info,
                              bool trivial_pathtarget);
extern void cost_functionscan(Path *path, PlannerInfo *root,
                              RelOptInfo *baserel, ParamPathInfo *param_info);
extern void cost_valuesscan(Path *path, PlannerInfo *root,
                            RelOptInfo *baserel, ParamPathInfo *param_info);
extern void cost_tablefuncscan(Path *path, PlannerInfo *root,
                               RelOptInfo *baserel, ParamPathInfo *param_info);
extern void cost_ctescan(Path *path, PlannerInfo *root,
                         RelOptInfo *baserel, ParamPathInfo *param_info);
extern void cost_namedtuplestorescan(Path *path, PlannerInfo *root,
                                     RelOptInfo *baserel, ParamPathInfo *param_info);
extern void cost_resultscan(Path *path, PlannerInfo *root,
                            RelOptInfo *baserel, ParamPathInfo *param_info);
extern void cost_recursive_union(Path *runion, Path *nrterm, Path *rterm);
extern void cost_sort(Path *path, PlannerInfo *root,
                      List *pathkeys, int input_disabled_nodes,
                      Cost input_cost, double tuples, int width,
                      Cost comparison_cost, int sort_mem,
                      double limit_tuples);
extern void cost_incremental_sort(Path *path,
                                  PlannerInfo *root, List *pathkeys, int presorted_keys,
                                  int input_disabled_nodes,
                                  Cost input_startup_cost, Cost input_total_cost,
                                  double input_tuples, int width, Cost comparison_cost, int sort_mem,
                                  double limit_tuples);
extern void cost_append(AppendPath *apath, PlannerInfo *root);
extern void cost_merge_append(Path *path, PlannerInfo *root,
                              List *pathkeys, int n_streams,
                              int input_disabled_nodes,
                              Cost input_startup_cost, Cost input_total_cost,
                              double tuples);
extern void cost_material(Path *path,
                          bool enabled, int input_disabled_nodes,
                          Cost input_startup_cost, Cost input_total_cost,
                          double tuples, int width);
extern void cost_agg(Path *path, PlannerInfo *root,
                     AggStrategy aggstrategy, const AggClauseCosts *aggcosts,
                     int numGroupCols, double numGroups,
                     List *quals,
                     int disabled_nodes,
                     Cost input_startup_cost, Cost input_total_cost,
                     double input_tuples, double input_width);
extern void cost_windowagg(Path *path, PlannerInfo *root,
                           List *windowFuncs, WindowClause *winclause,
                           int input_disabled_nodes,
                           Cost input_startup_cost, Cost input_total_cost,
                           double input_tuples);
extern void cost_group(Path *path, PlannerInfo *root,
                       int numGroupCols, double numGroups,
                       List *quals,
                       int input_disabled_nodes,
                       Cost input_startup_cost, Cost input_total_cost,
                       double input_tuples);
extern void initial_cost_nestloop(PlannerInfo *root,
                                  JoinCostWorkspace *workspace,
                                  JoinType jointype, uint64 enable_mask,
                                  Path *outer_path, Path *inner_path,
                                  JoinPathExtraData *extra);
extern void final_cost_nestloop(PlannerInfo *root, NestPath *path,
                                JoinCostWorkspace *workspace,
                                JoinPathExtraData *extra);
extern void initial_cost_mergejoin(PlannerInfo *root,
                                   JoinCostWorkspace *workspace,
                                   JoinType jointype,
                                   List *mergeclauses,
                                   Path *outer_path, Path *inner_path,
                                   List *outersortkeys, List *innersortkeys,
                                   int outer_presorted_keys,
                                   JoinPathExtraData *extra);
extern void final_cost_mergejoin(PlannerInfo *root, MergePath *path,
                                 JoinCostWorkspace *workspace,
                                 JoinPathExtraData *extra);
extern void initial_cost_hashjoin(PlannerInfo *root,
                                  JoinCostWorkspace *workspace,
                                  JoinType jointype,
                                  List *hashclauses,
                                  Path *outer_path, Path *inner_path,
                                  JoinPathExtraData *extra,
                                  bool parallel_hash);
extern void final_cost_hashjoin(PlannerInfo *root, HashPath *path,
                                JoinCostWorkspace *workspace,
                                JoinPathExtraData *extra);
extern void cost_gather(GatherPath *path, PlannerInfo *root,
                        RelOptInfo *rel, ParamPathInfo *param_info, double *rows);
extern void cost_gather_merge(GatherMergePath *path, PlannerInfo *root,
                              RelOptInfo *rel, ParamPathInfo *param_info,
                              int input_disabled_nodes,
                              Cost input_startup_cost, Cost input_total_cost,
                              double *rows);
extern void cost_subplan(PlannerInfo *root, SubPlan *subplan, Plan *plan);
extern void cost_qual_eval(QualCost *cost, List *quals, PlannerInfo *root);
extern void cost_qual_eval_node(QualCost *cost, Node *qual, PlannerInfo *root);
extern void compute_semi_anti_join_factors(PlannerInfo *root,
                                           RelOptInfo *joinrel,
                                           RelOptInfo *outerrel,
                                           RelOptInfo *innerrel,
                                           JoinType jointype,
                                           SpecialJoinInfo *sjinfo,
                                           List *restrictlist,
                                           SemiAntiJoinFactors *semifactors);
extern void set_baserel_size_estimates(PlannerInfo *root, RelOptInfo *rel);
extern double get_parameterized_baserel_size(PlannerInfo *root,
                                             RelOptInfo *rel,
                                             List *param_clauses);
extern double get_parameterized_joinrel_size(PlannerInfo *root,
                                             RelOptInfo *rel,
                                             Path *outer_path,
                                             Path *inner_path,
                                             SpecialJoinInfo *sjinfo,
                                             List *restrict_clauses);
extern void set_joinrel_size_estimates(PlannerInfo *root, RelOptInfo *rel,
                                       RelOptInfo *outer_rel,
                                       RelOptInfo *inner_rel,
                                       SpecialJoinInfo *sjinfo,
                                       List *restrictlist);
extern void set_subquery_size_estimates(PlannerInfo *root, RelOptInfo *rel);
extern void set_function_size_estimates(PlannerInfo *root, RelOptInfo *rel);
extern void set_values_size_estimates(PlannerInfo *root, RelOptInfo *rel);
extern void set_cte_size_estimates(PlannerInfo *root, RelOptInfo *rel,
                                   double cte_rows);
extern void set_tablefunc_size_estimates(PlannerInfo *root, RelOptInfo *rel);
extern void set_namedtuplestore_size_estimates(PlannerInfo *root, RelOptInfo *rel);
extern void set_result_size_estimates(PlannerInfo *root, RelOptInfo *rel);
extern void set_foreign_size_estimates(PlannerInfo *root, RelOptInfo *rel);
extern PathTarget *set_pathtarget_cost_width(PlannerInfo *root, PathTarget *target);
extern double compute_bitmap_pages(PlannerInfo *root, RelOptInfo *baserel,
                                   Path *bitmapqual, double loop_count,
                                   Cost *cost_p, double *tuples_p);
extern double compute_gather_rows(Path *path);
 
#endif                          /* COST_H */