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//usr/include/pgsql/server/optimizer/cost.h

/*-------------------------------------------------------------------------
 *
 * cost.h
 *	  prototypes for costsize.c and clausesel.c.
 *
 *
 * Portions Copyright (c) 1996-2012, 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/plannodes.h"
#include "nodes/relation.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.sample.conf */
#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_EFFECTIVE_CACHE_SIZE  16384		/* 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 */
extern PGDLLIMPORT double seq_page_cost;
extern PGDLLIMPORT double random_page_cost;
extern PGDLLIMPORT double cpu_tuple_cost;
extern PGDLLIMPORT double cpu_index_tuple_cost;
extern PGDLLIMPORT double cpu_operator_cost;
extern PGDLLIMPORT int effective_cache_size;
extern Cost disable_cost;
extern bool enable_seqscan;
extern bool enable_indexscan;
extern bool enable_indexonlyscan;
extern bool enable_bitmapscan;
extern bool enable_tidscan;
extern bool enable_sort;
extern bool enable_hashagg;
extern bool enable_nestloop;
extern bool enable_material;
extern bool enable_mergejoin;
extern bool enable_hashjoin;
extern int	constraint_exclusion;

extern double clamp_row_est(double nrows);
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_index(IndexPath *path, PlannerInfo *root,
		   double loop_count);
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);
extern void cost_subqueryscan(Path *path, PlannerInfo *root,
				  RelOptInfo *baserel, ParamPathInfo *param_info);
extern void cost_functionscan(Path *path, PlannerInfo *root,
				  RelOptInfo *baserel);
extern void cost_valuesscan(Path *path, PlannerInfo *root,
				RelOptInfo *baserel);
extern void cost_ctescan(Path *path, PlannerInfo *root, RelOptInfo *baserel);
extern void cost_recursive_union(Plan *runion, Plan *nrterm, Plan *rterm);
extern void cost_sort(Path *path, PlannerInfo *root,
		  List *pathkeys, Cost input_cost, double tuples, int width,
		  Cost comparison_cost, int sort_mem,
		  double limit_tuples);
extern void cost_merge_append(Path *path, PlannerInfo *root,
				  List *pathkeys, int n_streams,
				  Cost input_startup_cost, Cost input_total_cost,
				  double tuples);
extern void cost_material(Path *path,
			  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,
		 Cost input_startup_cost, Cost input_total_cost,
		 double input_tuples);
extern void cost_windowagg(Path *path, PlannerInfo *root,
			   List *windowFuncs, int numPartCols, int numOrderCols,
			   Cost input_startup_cost, Cost input_total_cost,
			   double input_tuples);
extern void cost_group(Path *path, PlannerInfo *root,
		   int numGroupCols, double numGroups,
		   Cost input_startup_cost, Cost input_total_cost,
		   double input_tuples);
extern void initial_cost_nestloop(PlannerInfo *root,
					  JoinCostWorkspace *workspace,
					  JoinType jointype,
					  Path *outer_path, Path *inner_path,
					  SpecialJoinInfo *sjinfo,
					  SemiAntiJoinFactors *semifactors);
extern void final_cost_nestloop(PlannerInfo *root, NestPath *path,
					JoinCostWorkspace *workspace,
					SpecialJoinInfo *sjinfo,
					SemiAntiJoinFactors *semifactors);
extern void initial_cost_mergejoin(PlannerInfo *root,
					   JoinCostWorkspace *workspace,
					   JoinType jointype,
					   List *mergeclauses,
					   Path *outer_path, Path *inner_path,
					   List *outersortkeys, List *innersortkeys,
					   SpecialJoinInfo *sjinfo);
extern void final_cost_mergejoin(PlannerInfo *root, MergePath *path,
					 JoinCostWorkspace *workspace,
					 SpecialJoinInfo *sjinfo);
extern void initial_cost_hashjoin(PlannerInfo *root,
					  JoinCostWorkspace *workspace,
					  JoinType jointype,
					  List *hashclauses,
					  Path *outer_path, Path *inner_path,
					  SpecialJoinInfo *sjinfo,
					  SemiAntiJoinFactors *semifactors);
extern void final_cost_hashjoin(PlannerInfo *root, HashPath *path,
					JoinCostWorkspace *workspace,
					SpecialJoinInfo *sjinfo,
					SemiAntiJoinFactors *semifactors);
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 *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,
							   double outer_rows,
							   double inner_rows,
							   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,
					   Plan *cteplan);
extern void set_foreign_size_estimates(PlannerInfo *root, RelOptInfo *rel);

/*
 * prototypes for clausesel.c
 *	  routines to compute clause selectivities
 */
extern Selectivity clauselist_selectivity(PlannerInfo *root,
					   List *clauses,
					   int varRelid,
					   JoinType jointype,
					   SpecialJoinInfo *sjinfo);
extern Selectivity clause_selectivity(PlannerInfo *root,
				   Node *clause,
				   int varRelid,
				   JoinType jointype,
				   SpecialJoinInfo *sjinfo);

#endif   /* COST_H */