Prefix   cardinality   has   been   estimated    for    database
  <str>.RMU/COLLECT  OPTIMIZER_STATISTICS  should  be  run  to get
  actual values.

  Explanation:  The Rdb query  optimzer  uses  prefix  cardinality
  statistics.    Running   RMU/COLLECT  OPTIMIZER_STATISTICS  will
  replace estimated or out of data cardinality values with  actual
  cardinality values.

  User Action:  Run RMU/COLLECT OPTIMIZER_STATISTICS  as  soon  as
  posssible.