2107{
2108 Oid table_oid = PG_GETARG_OID(0);
2109 text *att_text = PG_GETARG_TEXT_P(1);
2110 Datum geom_datum = PG_GETARG_DATUM(2);
2112 float8 selectivity = 0;
2114 int mode = 2;
2115
2116
2117 if ( ! PG_ARGISNULL(3) )
2119
2120
2122
2123 if ( ! nd_stats )
2124 elog(ERROR,
"stats for \"%s.%s\" do not exist", get_rel_name(table_oid),
text_to_cstring(att_text));
2125
2126
2127 if ( ! gserialized_datum_get_gbox_p(geom_datum, &gbox) )
2128 elog(ERROR, "unable to calculate bounding box from geometry");
2129
2131
2132
2134
2135 pfree(nd_stats);
2136 PG_RETURN_FLOAT8(selectivity);
2137}
char * gbox_to_string(const GBOX *gbox)
Allocate a string representation of the GBOX, based on dimensionality of flags.
static float8 estimate_selectivity(const GBOX *box, const ND_STATS *nd_stats, int mode)
This function returns an estimate of the selectivity of a search GBOX by looking at data in the ND_ST...
static int text_p_get_mode(const text *txt)
Utility function to see if the first letter of the mode argument is 'N'.
static ND_STATS * pg_get_nd_stats_by_name(const Oid table_oid, const text *att_text, int mode, bool only_parent)
Pull the stats object from the PgSQL system catalogs.
char * text_to_cstring(const text *textptr)
N-dimensional statistics structure.