#2101, sql functions for selectivity inspection

git-svn-id: http://svn.osgeo.org/postgis/trunk@10725 b70326c6-7e19-0410-871a-916f4a2858ee

diff --git a/postgis/geometry_estimate.c b/postgis/geometry_estimate.c
index 2aebf0a17af447e92a49c7fa70649d9795423707..461ebffeec7abf7f7cc6f44d19cf9b3ec1ae546a 100644 (file)
--- a/postgis/geometry_estimate.c
+++ b/postgis/geometry_estimate.c
@@ -116,9 +116,9 @@ static float8 estimate_selectivity(GBOX *box, GEOM_STATS *geomstats);
 
 Datum geometry_gist_sel_2d(PG_FUNCTION_ARGS);
 Datum geometry_gist_joinsel_2d(PG_FUNCTION_ARGS);
-Datum geometry_gist_read_selectivity(PG_FUNCTION_ARGS);
 Datum geometry_analyze_2d(PG_FUNCTION_ARGS);
 Datum geometry_estimated_extent(PG_FUNCTION_ARGS);
+Datum _postgis_geometry_sel(PG_FUNCTION_ARGS);
 
 
 #if ! REALLY_DO_JOINSEL
@@ -612,27 +612,34 @@ estimate_selectivity(GBOX *box, GEOM_STATS *geomstats)
 * Utility function to read the calculated selectivity for a given search
 * box and table/column. Used for debugging the selectivity code.
 */
-PG_FUNCTION_INFO_V1(geometry_gist_read_selectivity);
-Datum geometry_gist_read_selectivity(PG_FUNCTION_ARGS)
+PG_FUNCTION_INFO_V1(_postgis_geometry_sel);
+Datum _postgis_geometry_sel(PG_FUNCTION_ARGS)
 {
        HeapTuple stats_tuple;
        float4 *floatptr;
-       Oid table_oid = PG_GETARG_INT32(0);
-       int16 attr_num = PG_GETARG_INT32(1);
+       Oid table_oid = PG_GETARG_OID(0);
        Datum geom_datum = PG_GETARG_DATUM(2);
+       text *att_text = PG_GETARG_TEXT_P(1);
+       const char *att_name = text2cstring(att_text);
        int rv;
        GBOX gbox;
        int32 nvalues = 0;
        float8 selectivity = 0;
+       AttrNumber att_num;
 
        /* Calculate the gbox */
        if ( ! gserialized_datum_get_gbox_p(geom_datum, &gbox) )
                elog(ERROR, "Unable to calculate bounding box from geometry");
+
+       /* Get the attribute number */
+       att_num = get_attnum(table_oid, att_name);
+       if  ( ! att_num )
+               elog(ERROR, "Unable to attribute number for attribute '%s'", att_name);
        
        /* First pull the stats tuple */
-       stats_tuple = SearchSysCache2(STATRELATT, ObjectIdGetDatum(table_oid), Int16GetDatum(attr_num));
+       stats_tuple = SearchSysCache2(STATRELATT, table_oid, att_num);
        if ( ! stats_tuple )
-               elog(ERROR, "Unable to retreive stats tuple for oid(%d) attrnum(%d), run ANALYZE?", table_oid, attr_num);
+               elog(ERROR, "Unable to retreive stats tuple for oid(%d) attrnum(%d), run ANALYZE?", table_oid, att_num);
                
        /* Then read the geom status histogram from that */
        rv = get_attstatsslot(stats_tuple, 0, 0, STATISTIC_KIND_GEOMETRY, InvalidOid, NULL, NULL, NULL, &floatptr, &nvalues);

diff --git a/postgis/postgis.sql.in.c b/postgis/postgis.sql.in.c
index 39c75bbe66fd3068a8137e5b613aeb6693a888c6..2dd174074be27cb90435dab24d71dd865a3eba2f 100644 (file)
--- a/postgis/postgis.sql.in.c
+++ b/postgis/postgis.sql.in.c
@@ -429,31 +429,10 @@ CREATE OR REPLACE FUNCTION geometry_gist_joinsel_2d(internal, oid, internal, sma
        LANGUAGE 'c';
 
 -- Availability: 2.1.0
-CREATE OR REPLACE FUNCTION geometry_gist_read_selectivity(relid oid, attnum int2, geom geometry)
+CREATE OR REPLACE FUNCTION _postgis_geometry_sel(tbl regclass, att_name text, geom geometry)
        RETURNS float8
-       AS 'MODULE_PATHNAME', 'geometry_gist_read_selectivity'
-       LANGUAGE 'c';
-       
--- Availability: 2.1.0
-CREATE OR REPLACE FUNCTION geometry_gist_selectivity(schemaname varchar, tablename varchar, attrname varchar, geom geometry)
-       RETURNS float8
-       AS $$
-         DECLARE
-               selectivity float8;
-         BEGIN
-               SELECT geometry_gist_read_selectivity(r.oid, a.attnum, 'SRID=4326;LINESTRING(0 0, 1 1)'::geometry)
-               INTO selectivity
-               FROM pg_class r 
-           JOIN pg_attribute a ON (r.oid = a.attrelid) 
-           JOIN pg_namespace n ON (r.relnamespace = n.oid) 
-           WHERE  n.nspname = $1 AND r.relname = $2 and a.attname = $3;
-           IF NOT FOUND THEN
-                  RAISE EXCEPTION 'Couldn''t find table? column?';
-               END IF;
-               RETURN selectivity;
-         END;
-       $$
-       LANGUAGE 'plpgsql';
+       AS 'MODULE_PATHNAME', '_postgis_geometry_sel'
+       LANGUAGE 'c' STRICT;