Specifies the number of row caches for which slots are reserved
    in the database.

    You can use the RESERVE CACHE SLOTS clause to reserve slots in
    the database root file for furture use by the ADD CACHE clause.
    You can only add row caches if row cache slots are available.
    Slots become available after you issue a DROP CACHE clause or a
    RESERVE CACHE SLOTS clause.

    You cannot reduce the number of reserved slots for row caching.
    If you reserve 10 slots and later reserve 5 slots, a total of 15
    slots are reserved for row caches.