Optional database functions

In addition to logical relationships and secondary indexes, which are described in separate topics, IMS™ databases support a variety of optional functions that you can choose to implement depending on the database type you are using and the needs of your installation.

The optional functions described in this topic do not apply to GSAM, MSDB, HSAM, and SHSAM databases. Only the variable-length segment function, the Segment Edit/Compression exit routine, and the Data Capture exit routine apply to DEDBs.