CREATE FUNCTION "URX_PUBLIC"."_overview_constraint"(ov raster, factor integer, refschema name, reftable name, refcolumn name) 
 RETURNS boolean AS 
$BODY$ SELECT COALESCE((SELECT TRUE FROM "URX_PUBLIC".raster_columns WHERE r_table_catalog = current_database() AND r_table_schema = $3 AND r_table_name = $4 AND r_raster_column = $5), FALSE) $BODY$
 LANGUAGE 'sql' STABLE;