RDOHELP72.HLB  —  DEFINE_INDEX, Format  index-storage-clause  default-threshold-clause
  (B)0default-threshold-clause =

  qq> DEFAULT THRESHOLDS ARE qqk
   lqqqqqqqqqqqqq<qqqqqqqqqqqqqj
   mq> ( qq> val1 qwqqqqqqqqqqq>qqqqqqqqqqwq> ) qq>
                   mq> ,val2 qqwqqqqq>qqqqu
                               mq> ,val3 qj

    Specifies associated threshold values for each storage area with
    uniform format that is NOT specified in the index-within-clause.
    By setting threshold values, you can make sure that Oracle Rdb does
    not overlook a page with sufficient space to store compressed
    data.

    The threshold values specify when the page is marked as FULL
    in the SPAM page free space inventory lists. For example,
    if you set default values of 70, 85, and 95 percent, ranges
    of guaranteed free space on each data page are 30, 15, and 5
    percent, respectively. If you do not set default values, the
    values are (0,0,0). With values of (0,0,0), Oracle Rdb will use the
    record length when setting the SPAM fullness. Oracle Rdb will never
    store a record on a page at threshold 3. The value you set for
    the highest threshold can be used to reserve space on the page
    for future record growth.

    If you specify a value of 40 for the "val1" parameter, but do not
    specify values for the "val2" or "val3" parameters, the threshold
    values will be set at (40,100,100).

    If you use data compression, you should use logical area
    thresholds to obtain optimum storage performance.
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