Blocks_Per_Page=n

    Specifies a new page size for the storage area to which it is
    applied. You cannot decrease the page size of a storage area.

    If you attempt to change the page size during an online Move_
    Area operation, you might receive a PAGESIZETOOBIG error message.
    Changing the page size sometimes requires that Oracle Rdb change
    the buffer size for the database also (because buffers must be
    large enough to hold at least one page from each area). However,
    the buffer size cannot change if other users are accessing the
    database.

    You might want to increase the page size in storage areas
    containing hash indexes that are close to full. By increasing
    the page size in such a situation, you prevent the storage area
    from extending.

    The Blocks_Per_Page qualifier is a positional qualifier.