postgresql7.1 select site_node__url(n.node_id) as url, n.node_id, n.directory_p, n.pattern_p, n.object_id, o.object_type, n.package_key, n.package_id from acs_objects o left outer join (select n.node_id, n.directory_p, n.pattern_p, n.object_id, p.package_key, p.package_id from site_nodes n, apm_packages p where n.object_id = p.package_id) n on n.object_id = o.object_id