The data portion

The data portion of a segment contains one or more data elements. The data is processed and unlike the prefix portion of the segment, seen by an application program.

The application program accesses segments in a database using the name of the segment type. If an application program needs to reference part of a segment, a field name can be defined to IMS for that part of the segment. Field names are used in segment search arguments (SSAs) to qualify calls. An application program can see data even if you do not define it as a field. But an application program cannot qualify an SSA on the data unless it is defined as a field.

The maximum number of fields that you can define for a segment type is 255. The maximum number of fields that can be defined for a database is 1000. Note that 1000 refers to types of fields in a database, not occurrences. The number of occurrences of fields in a database is limited only by the amount of storage you have defined for your database.