_id := id
        FROM    _user
        WHERE   login=_login and pass=_pass;

SELECT current_setting('search_path');

CREATE OR REPLACE FUNCTION proces(
    _login character,
    _pass character)
  RETURNS integer AS
$BODY$
DECLARE _id integer;
BEGIN
   _id:=id
   FROM    _user
   WHERE   login=_login and pass=_pass;

   RETURN _id;
END;
$BODY$
  LANGUAGE plpgsql VOLATILE SECURITY DEFINER
  COST 100;

SELECT nsp.nspname, c.relname FROM pg_class AS c INNER JOIN pg_namespace AS nsp ON c.relnamespace = nsp.oid AND lower(c.relname) = '_user';

SELECT nsp.nspname, concat('"', c.relname, '"') AS relname FROM pg_class AS c INNER JOIN pg_namespace AS nsp ON c.relnamespace = nsp.oid AND lower(c.relname) = '_user';