Is not working with postgresql

* warning: pg_query() [function.pg-query]: Query failed: ERRO: coluna "n.title" deve aparecer na cláusula GROUP BY ou ser utilizada em uma função de agregação in /var/www/dp-relevance/includes/database.pgsql.inc on line 139.
* user warning: query: SELECT n.nid, n.title, (count(*) * (IF(td.vid = 2, 5, 2))) AS relevance FROM node n, term_node tn, term_data td WHERE n.nid <> 7 AND td.tid = tn.tid AND tn.nid = n.nid AND tn.tid in (SELECT tn.tid FROM term_node tn WHERE tn.nid = 7) AND td.vid IN (2,1) GROUP BY n.nid ORDER BY relevance DESC,n.nid DESC LIMIT 5 in /var/www/dp-relevance/sites/all/modules/relevance/relevance.module on line 199.