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/*-------------------------------------------------------------------------
*
* rtstrat.c
* strategy map data for rtrees.
*
* Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/access/rtree/Attic/rtstrat.c,v 1.22 2003/11/09 21:30:35 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/rtree.h"
/*
* Here's something peculiar to rtrees that doesn't apply to most other
* indexing structures: When we're searching a tree for a given value, we
* can't do the same sorts of comparisons on internal node entries as we
* do at leaves. The reason is that if we're looking for (say) all boxes
* that are the same as (0,0,10,10), then we need to find all leaf pages
* that overlap that region. So internally we search for overlap, and at
* the leaf we search for equality.
*
* This array maps leaf search operators to the internal search operators.
* We assume the normal ordering on operators:
*
* left, left-or-overlap, overlap, right-or-overlap, right, same,
* contains, contained-by
*/
static const StrategyNumber RTOperMap[RTNStrategies] = {
RTOverLeftStrategyNumber,
RTOverLeftStrategyNumber,
RTOverlapStrategyNumber,
RTOverRightStrategyNumber,
RTOverRightStrategyNumber,
RTContainsStrategyNumber,
RTContainsStrategyNumber,
RTOverlapStrategyNumber
};
StrategyNumber
RTMapToInternalOperator(StrategyNumber strat)
{
Assert(strat > 0 && strat <= RTNStrategies);
return RTOperMap[strat - 1];
}
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