Reserve=(Area=n,Aij=n)

    Reserves space in the database root file for storage areas or
    .aij files, or both. Replace the character n with the number of
    storage areas or .aij files for which you want to reserve space.

    Note that you cannot reserve areas for a single-file database.
    You can reserve .aij files for a single-file database, but once
    the database is converted, you cannot alter that reservation
    unless you backup and restore the database.

    This qualifier is useful if, when you are converting your
    database, you anticipate the need for additional storage areas
    or .aij files. Because the addition of new storage areas or .aij
    files requires that users not be attached to the database, adding
    them while the database is being converted minimizes the time
    that the database is inaccessible to users.

    By default, one .aij file and no storage area files are reserved.