Specifies the number of journal files for which slots are
    reserved in the database. If your database is not a multifile
    database, you cannot reserve additional slots later using the
    ALTER DATABASE statement.

    You must reserve slots before you can add journal files to the
    database.

    See the ALTER DATABASE statement for more information about
    adding journal files and enabling the journaling feature.

    The following SQL statements create a multifile database and
    reserve 5 slots for future journal files.

    SQL> CREATE DATABASE FILENAME test
    cont>    RESERVE 5 JOURNALS
    cont>    CREATE STORAGE AREA sa_one
    cont>       ALLOCATION IS 10 PAGES;