Extrapartition queues

Extrapartition queues (data sets) reside on any sequential device (DASD, tape, printer, and so on) that are accessible by programs outside (or within) the CICS® region.

In general, sequential extrapartition queues are used for storing and retrieving data outside the CICS region. For example, one task may read data from a remote terminal, edit the data, and write the results to a data set for subsequent processing in another region. Logging data, statistics, and transaction error messages are examples of data that can be written to extrapartition queues. In general, extrapartition data created by CICS is intended for subsequent batched input to non-CICS programs. Data can also be routed to an output device such as a printer.

Data directed to or from an external destination is referred to as extrapartition data and consists of sequential records that are fixed-length or variable-length, blocked or unblocked. The record format for an extrapartition destination must be defined in a TDQUEUE resource definition by the system programmer. See Defining TDQUEUE resources for details about queue definitions.

If you create a data set definition for the extrapartition queue using JCL, the DD statement for the data set must not include the FREE=CLOSE operand. If you do specify FREE=CLOSE, attempts to read the queue after the queue has been closed and then reopened can receive an IOERR condition. Defining data sets to CICS has more information about defining data sets to CICS.