the "<str>" clause can not be  used  with  some  ALTER  DATABASE
  clauses

  Explanation:  You attempted to mix  the  specified  clause  with
  other ALTER DATABASE clauses that modify storage areas, template
  areas  or  database  cache  objects.   This  is  not   currently
  supported.

  User Action:  Execute two separate  ALTER  DATABASE  statements,
  one  containing  structure  altering  clauses,  and one with the
  remaining attributes.