postgres/src/backend/utils/adt/geo_selfuncs.c

/*-------------------------------------------------------------------------
 *
 * geo-selfuncs.c--
 *    Selectivity routines registered in the operator catalog in the
 *    "oprrest" and "oprjoin" attributes.
 *
 * Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *    $Header: /cvsroot/pgsql/src/backend/utils/adt/geo_selfuncs.c,v 1.1 1997/03/09 20:40:57 momjian Exp $
 *
 *	XXX These are totally bogus.
 *
 *-------------------------------------------------------------------------
 */
#include "postgres.h"

#include "access/attnum.h"
#include "utils/geo-decls.h"	/* where function declarations go */
#include "utils/palloc.h"
#include "utils/builtins.h"

float64
areasel(Oid opid, 
	Oid relid, 
	AttrNumber attno, 
	char *value,
	int32 flag)
{
    float64	result;
    
    result = (float64) palloc(sizeof(float64data));
    *result = 1.0 / 4.0;
    return(result);
}

float64
areajoinsel(Oid opid,
	    Oid relid,
	    AttrNumber attno,
	    char *value,
	    int32 flag)
{
    float64	result;
    
    result = (float64) palloc(sizeof(float64data));
    *result = 1.0 / 4.0;
    return(result);
}

/*
 *  Selectivity functions for rtrees.  These are bogus -- unless we know
 *  the actual key distribution in the index, we can't make a good prediction
 *  of the selectivity of these operators.
 *
 *  In general, rtrees need to search multiple subtrees in order to guarantee
 *  that all occurrences of the same key have been found.  Because of this,
 *  the heuristic selectivity functions we return are higher than they would
 *  otherwise be.
 */

/*
 *  left_sel -- How likely is a box to be strictly left of (right of, above,
 *		below) a given box?
 */

float64
leftsel(Oid opid,
	Oid relid,
	AttrNumber attno,
	char *value,
	int32 flag)
{
    float64	result;
    
    result = (float64) palloc(sizeof(float64data));
    *result = 1.0 / 6.0;
    return(result);
}

float64
leftjoinsel(Oid opid,
	    Oid relid,
	    AttrNumber attno,
	    char *value,
	    int32 flag)
{
    float64	result;
    
    result = (float64) palloc(sizeof(float64data));
    *result = 1.0 / 6.0;
    return(result);
}

/*
 *  contsel -- How likely is a box to contain (be contained by) a given box?
 */
float64
contsel(Oid opid,
	Oid relid,
	AttrNumber attno,
	char *value,
	int32 flag)
{
    float64	result;
    
    result = (float64) palloc(sizeof(float64data));
    *result = 1.0 / 10.0;
    return(result);
}

float64
contjoinsel(Oid opid,
	    Oid relid,
	    AttrNumber attno,
	    char *value,
	    int32 flag)
{
    float64	result;
    
    result = (float64) palloc(sizeof(float64data));
    *result = 1.0 / 10.0;
    return(result);
}