Syntax options:

    THRESHOLDS ARE ( val1 [,val2 [,val3] ] )

    Specifies one, two, or three threshold values for mixed format
    pages. The threshold values represent a fullness percentage on a
    data page and establish three possible ranges of guaranteed free
    space on the data pages. When a data page reaches the percentage
    defined by a given threshold value, the space area management
    (SPAM) entry for the data page is updated to reflect the new
    fullness percentage and its remaining free space.

    The default threshold values for mixed areas, if not specified,
    are (70,85,95), which indicates that the nominal record size
    should be used for SPAM threshold calculations. Oracle Rdb never
    stores a record on a page at the third threshold. The value you
    set for the highest threshold can be used to reserve space on the
    page for future record growth.

    When only val1 is specified, this is equivalent to (val1, 100,
    100). When val1 and val2 are specified, this is equivalent to
    (val1, val2, 100). The trailing, unspecified thresholds default
    to 100 percent. For example, THRESHOLDS ARE (40) would appear as
    (40, 100, 100).

    You cannot specify the THRESHOLDS storage area parameter unless
    you also explicitly specify PAGE FORMAT IS MIXED.

    For more information about setting space area management
    parameters, see the Oracle Rdb Guide to Database Maintenance.