Enterprise COBOL for z/OS, Version 4.2, Programming Guide

To use an alternate index for a VSAM KSDS file, you need to define a data set called the alternate index (AIX) by using access method services.

The AIX contains one record for each value of a given alternate key.
The records are in sequential order by alternate-key value.
Each record contains the corresponding primary keys of all records in the associated indexed files that contain the alternate-key value.

Related tasks