DL/I returns with secondary indexes

The term key of the pointer segment refers to the key as perceived by the application program. That is, the key does not include subsequent fields. IMS places this key in the position where the root key would be located if you had not used a secondary index—in the left-most bytes of the key feedback area.

The PATIENT segment that IMS returns to the application program's I/O area looks just as it would if you had not used secondary indexing. The key feedback area, however, contains something different. The concatenated key that IMS returns is the same, except that, instead of giving you the key for the segment you requested (the key for the PATIENT segment), IMS gives you the search portion of the key of the secondary index (the key for the segment in the INDEX database).

If you try to insert or replace a segment that contains a secondary index source field that is a duplicate of one that is already reflected in the secondary index, IMS returns an NI status code. An NI status code is returned only for batch programs that log to direct-access storage. Otherwise, the application program is abnormally terminated. You can avoid having your program terminated by making sure a duplicate index source field does not exist. Before inserting a segment, try to retrieve the segment using the secondary index source field as qualification.