Specifies one, two, or three default threshold values for logical
    areas in storage areas with uniform format pages. The threshold
    values (val1, val2, and val3) 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.

    Oracle Rdb never stores a record 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).

    If no thresholds are specified for the area, the default is
    (0,0,0). This causes the SPAM algorithm to set thresholds based
    on the nominal record length for the logical area; for example,
    the node size for the index or the uncompressed length of the row
    for a table.

    You cannot specify the thresholds for the storage map attribute
    for any area that is a mixed page format. If you have a mixed
    page format, set the thresholds for the storage area using the
    ADD STORAGE AREA or CREATE STORAGE AREA clause of the ALTER
    DATABASE, CREATE DATABASE, or IMPORT statements.