Pull the stats object from the PgSQL system catalogs.
Used by the selectivity functions and the debugging functions.
965 HeapTuple stats_tuple = NULL;
971 POSTGIS_DEBUGF(2,
"searching whole tree stats for \"%s\"", get_rel_name(table_oid)? get_rel_name(table_oid) :
"NULL");
972 stats_tuple = SearchSysCache3(STATRELATTINH, ObjectIdGetDatum(table_oid), Int16GetDatum(att_num), BoolGetDatum(
true));
974 POSTGIS_DEBUGF(2,
"found whole tree stats for \"%s\"", get_rel_name(table_oid)? get_rel_name(table_oid) :
"NULL");
977 if ( only_parent || ! stats_tuple )
979 POSTGIS_DEBUGF(2,
"searching parent table stats for \"%s\"", get_rel_name(table_oid)? get_rel_name(table_oid) :
"NULL");
980 stats_tuple = SearchSysCache3(STATRELATTINH, ObjectIdGetDatum(table_oid), Int16GetDatum(att_num), BoolGetDatum(
false));
982 POSTGIS_DEBUGF(2,
"found parent table stats for \"%s\"", get_rel_name(table_oid)? get_rel_name(table_oid) :
"NULL");
986 POSTGIS_DEBUGF(2,
"stats for \"%s\" do not exist", get_rel_name(table_oid)? get_rel_name(table_oid) :
"NULL");
991 ReleaseSysCache(stats_tuple);
995 "histogram for attribute %d of table \"%s\" does not exist?",
996 att_num, get_rel_name(table_oid));
static ND_STATS * pg_nd_stats_from_tuple(HeapTuple stats_tuple, int mode)
N-dimensional statistics structure.