Specifies the number of storage areas for which slots are to
    reserve in the database. The number of slots for storage areas
    must be a positive number greater than zero.

    You can use the RESERVE STORAGE AREA clause to reserve slots
    in the database root file for future use by the ADD STORAGE
    AREA clause of the ALTER DATABASE statement. Storage areas can
    be added only if there are storage area slots available. Slots
    become available after a DROP STORAGE AREA clause or a RESERVE
    STORAGE AREA clause is issued.

    This feature is additive in nature. In other words, the number
    of reserved slots for storage areas cannot be decreased once
    the RESERVE clause is issued. If you reserve 10 slots and later
    reserve 5 slots, you have a total of 15 reserved slots for
    storage areas.

    You must reserve slots or delete an existing storage area before
    you can add new storage areas to the database.

    If you do not specify the RESERVE STORAGE AREA clause, the
    default number of reserved storage areas is zero.