Sort considerations—Index Build function

The Index Build function provides the following methods for determining the size of these data sets:

1. The Index Build function passes estimated record counts to the Sort utility from the values provided in the FILSZ keyword (FILSZ).
2. If you do not supply a FILSZ value for an index and use the IDCAMS keyword, the Index Build function extracts the records counts from the ICF Catalog before performing the IDCAMS DELETE/DEFINE of the index. These counts are then passed to the Sort utility. For more information, see IDCAMS.
3. If the record counts are not available from method 1 or 2 above, the Index Build uses the value from the SORTWORK keyword (SORTWORK).
4. If none of the methods listed above are available, the Index Build function uses the values from the installation default module (DLIGSET0).

If method 1 or 2 is used, the Sort utility allocates appropriately sized sort work data sets and is able to optimize its use of memory. If method 3 or 4 is used, the Index Build function allocates the same size work files for all sorts and the Sort utility uses system defined default values for its memory allocation. For more information, see SIUSORT.