cost.h

关系型数据库 Postgresql 6.5.2

/*-------------------------------------------------------------------------
 *
 * cost.h
 *	  prototypes for costsize.c and clausesel.c.
 *
 *
 * Copyright (c) 1994, Regents of the University of California
 *
 * $Id: cost.h,v 1.20 1999/05/25 22:43:04 momjian Exp $
 *
 *-------------------------------------------------------------------------
 */
#ifndef COST_H
#define COST_H

#include "nodes/nodes.h"
#include "nodes/parsenodes.h"
#include "nodes/pg_list.h"
#include "nodes/relation.h"

/*
 * prototypes for costsize.c
 *	  routines to compute costs and sizes
 */
extern bool _enable_seqscan_;
extern bool _enable_indexscan_;
extern bool _enable_sort_;
extern bool _enable_hash_;
extern bool _enable_nestloop_;
extern bool _enable_mergejoin_;
extern bool _enable_hashjoin_;

extern Cost cost_seqscan(int relid, int relpages, int reltuples);
extern Cost cost_index(Oid indexid, int expected_indexpages, Cost selec,
		   int relpages, int reltuples, int indexpages,
		   int indextuples, bool is_injoin);
extern Cost cost_sort(List *pathkeys, int tuples, int width);
extern Cost cost_nestloop(Cost outercost, Cost innercost, int outertuples,
			  int innertuples, int outerpages, bool is_indexjoin);
extern Cost cost_mergejoin(Cost outercost, Cost innercost,
			   List *outersortkeys, List *innersortkeys,
		   int outersize, int innersize, int outerwidth, int innerwidth);
extern Cost cost_hashjoin(Cost outercost, Cost innercost, List *outerkeys,
			  List *innerkeys, int outersize, int innersize,
			  int outerwidth, int innerwidth);
extern int	compute_rel_size(RelOptInfo *rel);
extern int	compute_rel_width(RelOptInfo *rel);
extern int	compute_joinrel_size(JoinPath *joinpath);
extern int	page_size(int tuples, int width);

/*
 * prototypes for fuctions in clausesel.h
 *	  routines to compute clause selectivities
 */
extern void set_clause_selectivities(List *restrictinfo_list, Cost new_selectivity);
extern Cost product_selec(List *restrictinfo_list);
extern void set_rest_relselec(Query *root, List *rel_list);
extern void set_rest_selec(Query *root, List *restrictinfo_list);
extern Cost compute_clause_selec(Query *root,
					 Node *clause, List *or_selectivities);

#endif	 /* COST_H */