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

    The default thresholds are 70, 85, and 95 percent. When
    THRESHOLDS ARE is used, the first threshold value is required.
    If you specify only one or two values, unspecified values default
    to 100 percent. You can specify the THRESHOLDS option only on a
    storage area for a multifile database. Threshold values can be
    set for storage areas with MIXED or UNIFORM storage area page
    formats.