Index <str> is also being dropped.

  Explanation:  When you issue the DROP TABLE statement, SQL also
  drops all indexes that use that table.  Also, when you issue the
  DROP SCHEMA or DROP CATALOG statement and specify CASCADE
  behavior, SQL drops all of the objects in that schema or catalog
  and all of the objects referenced by any objects being dropped.
  This message notifies you which indices those are.  It is
  informational only.

  User Action:  None.