SELECT n.nspname as schema, 
       c.relname as table
  FROM pg_class c
  JOIN pg_namespace n ON (n.oid =c.relnamespace )
 WHERE relkind = 'r' AND
       relname NOT LIKE 'pg_%' AND
       relname NOT LIKE 'sql_%' AND
       relhaspkey = FALSE
ORDER BY n.nspname, c.relname;