Transient data control

The CICS® transient data control facility provides a generalized queuing facility. Data can be queued (stored) for subsequent internal or external processing. Selected data, specified in the application program, can be routed to or from predefined symbolic intrapartition or extrapartition transient data queues.

Transient data queues are intrapartition if they are associated with a facility allocated to the CICS region, and extrapartition if the data is directed to a destination that is external to the CICS region. Transient data queues must be defined and installed before first reference by an application program.

Intrapartition and extrapartition queues can be used as indirect queues. Indirect queues provide some flexibility in program maintenance in that data can be routed to one of several queues with only the transient data definition, and not the program itself, having to be changed. When a transient data definition has been changed, application programs continue to route data to the queue using the original symbolic name; however, this name is now an indirect queue that refers to the new symbolic name. Because indirect queues are established by using transient data resource definitions, the application programmer does not usually have to be concerned with how this is done. Further information about transient data resource definition is in TDQUEUE resources.

Operations on transient data queues

You can:
  • Write data to a transient data queue (WRITEQ TD command)
  • Read data from a transient data queue (READQ TD command)
  • Delete the contents of an intrapartition transient data queue (DELETEQ TD command)

If the TD keyword is omitted, the command is assumed to be for temporary storage. See Temporary storage control for more information about temporary storage.

Java and C++

The application programming interface described here is the CICS API, which is not used in Java™ programs. For information about Java programs using the JCICS classes to access transient data services, see Java development using JCICS and the JCICS Javadoc documentation. For information about C®++ programs using the CICS C++ classes, see Using the CICS foundation classes.