Specifies the number of data pages between SPAM pages in the
    physical storage area file, and thus the maximum of data pages
    each SPAM page will manage. The default, and also the minimum
    interval, is 256 data pages. The first page of each storage
    area is a SPAM page. The interval you specify determines where
    subsequent SPAM pages are to be inserted, provided there are
    enough data pages in the storage file to require more SPAM pages.

    You can specify the INTERVAL option only on a storage area for a
    multifile database. The storage area page format must be MIXED.