Alters a database in any of the following ways:

    o  For single-file and multifile databases, the ALTER DATABASE
       statement changes the characteristics of the database root
       file.

       The ALTER DATABASE statement lets you override certain
       characteristics specified in the database root file parameters
       of the CREATE DATABASE statement, such as whether or not a
       snapshot file is disabled. In addition, ALTER DATABASE lets
       you control other characteristics that you cannot specify in
       the CREATE DATABASE database root file parameters, such as
       whether or not after-image journaling is enabled.

    o  For single-file and multifile databases, the ALTER DATABASE
       statement changes the storage area parameters.

    o  For multifile databases only, the ALTER DATABASE statement
       adds, alters, or deletes storage areas.