WITH T AS
  (SELECT
    U.NICK,
    COUNT(*) AS TOTAL,
    R.REFERREDNODE
  FROM REFERU R, USER U
  WHERE
    R.REFERREDNODE IS NOT NULL AND
    R.REFERREDNODE = U.NODEID AND
    NODEID > 0 AND
    VISIBLE = 'Y'
  GROUP BY
    U.NICK,
    R.REFERREDNODE
  ORDER BY
    COUNT(*) DESC
  FETCH FIRST 5 ROWS ONLY),
U AS
  (SELECT
    T.NICK AS NICK,
    MAX(R.MSGID) AS MAXID,
    MIN(R.MSGID) AS MINID
  FROM
    USER, T, LOGS L, REFERU R
  WHERE
    T.REFERREDNODE = R.REFERREDNODE AND
    R.MSGID = L.MSGID AND
    USER.NICK = L.FROM AND
    VISIBLE = 'Y' AND
    NODEID > 0
  GROUP BY T.NICK)
SELECT
  T.NICK,
  T.TOTAL,
  LMAX.FROM,
  LMIN.FROM
FROM
  T,
  U,
  LOGS LMAX,
  LOGS LMIN
WHERE
  U.MAXID = LMAX.MSGID AND
  U.MINID = LMIN.MSGID AND
  T.NICK  = U.NICK
ORDER BY
  T.TOTAL DESC,
  U.MAXID DESC