数据库系统

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hashstrat.c：源码内容

							/*-------------------------------------------------------------------------
 *
 * btstrat.c
 *	  Srategy map entries for the btree indexed access method
 *
 * Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *	  $Header: /usr/local/cvsroot/pgsql/src/backend/access/hash/hashstrat.c,v 1.13.2.1 1999/08/02 05:24:36 scrappy Exp $
 *
 *-------------------------------------------------------------------------
 */
#include "postgres.h"
/*
 *	only one valid strategy for hash tables: equality.
 */
#ifdef NOT_USED
static StrategyNumber HTNegate[1] = {
	InvalidStrategy
};
static StrategyNumber HTCommute[1] = {
	HTEqualStrategyNumber
};
static StrategyNumber HTNegateCommute[1] = {
	InvalidStrategy
};
static StrategyEvaluationData HTEvaluationData = {
	/* XXX static for simplicity */
	HTMaxStrategyNumber,
	(StrategyTransformMap) HTNegate,
	(StrategyTransformMap) HTCommute,
	(StrategyTransformMap) HTNegateCommute,
	{NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL}
};
#endif
/* ----------------------------------------------------------------
 *		RelationGetHashStrategy
 * ----------------------------------------------------------------
 */
#ifdef NOT_USED
static StrategyNumber
_hash_getstrat(Relation rel,
			   AttrNumber attno,
			   RegProcedure proc)
{
	StrategyNumber strat;
	strat = RelationGetStrategy(rel, attno, &HTEvaluationData, proc);
	Assert(StrategyNumberIsValid(strat));
	return strat;
}
#endif
#ifdef NOT_USED
static bool
_hash_invokestrat(Relation rel,
				  AttrNumber attno,
				  StrategyNumber strat,
				  Datum left,
				  Datum right)
{
	return (RelationInvokeStrategy(rel, &HTEvaluationData, attno, strat,
								   left, right));
}
#endif

						