File Pair List Verification

IBM® Connect:Direct® generates the statistics file pair list from the initialization parameters STAT.DSN.BASE and STAT.FILE.PAIRS. See STAT.DSN.BASE = dsname base STAT.FILE.PAIRS = number for an example of a file pair list.

The IBM Connect:Direct statistics facility processes the statistics file pair list in a circular, or wrap-around fashion. The system maintains statistics records in strictly chronological order both within each file pair, and with regard to the file pairs in the list.

At DTF initialization, unless STAT.INIT=COLD is specified in the initialization parameters, IBM Connect:Direct verifies that the order of the file pairs is valid. This verification is done by examining the date and time range of each non-empty file pair in the list. These must be in strictly ascending order throughout the list, except across the wrap point. Empty file pairs may appear anywhere in the list.

Changing the Number of File Pairs

It can be useful to periodically change the number of file pairs in the list. To change the number of file pairs, change the STAT.FILE.PAIRS initialization parameter which specifies the number of file pairs. This action adds to or removes from the end of the list.

  • Add empty file pairs to the end of the list unless you specify STAT.INIT=COLD.
  • Remove records from the end of the list by reducing the STAT.FILE.PAIRS value. When you remove these records, they become unavailable and can in some cases leave gaps in the statistics data. You may want to archive these records before removing them.