text: SELECT database,
          relation,
          n.nspname,
          c.relname,
          pid,
          a.usename,
          locktype,
          mode,
          granted,
          tuple
  FROM pg_lock l
  JOIN pg_class c ON (c.oid = l.relation)
  JOIN pg_namespace n ON (n.oid = c.relnamespace)
  JOIN pg_stat_activity a ON (a.procpid = l.pid)
  ORDER BY database,
              relation,
              pid;