Setting up data sets for transient data

Data sets that are used for transient data queues can be intrapartition or extrapartition. The transient data intrapartition data set is a VSAM entry-sequenced data set (ESDS) that is used for queuing messages and data within the CICS® region. Transient data extrapartition data sets are sequential files, normally on disk or tape; you can use the queue to send and receive data outside the CICS region.

About this task

Messages or other data are addressed to a symbolic queue that you define as either intrapartition or extrapartition using the CEDA transaction. The queues can be used as indirect destinations to route messages or data to other queues. System messages that CICS produces are commonly sent to transient data queues, either intrapartition or extrapartition.

Procedure

  1. Define all of the queues that CICS uses in your CICS region.
    Although the omission of any of the queues does not cause a CICS failure, you lose important information about your CICS region if CICS cannot write its data to the required queue.
    1. Use the sample definitions in group DFHDCTG to define the required queues.
      See TDQUEUE resources for a summary.
    2. Take a backup copy of the changes that you made to DFHDCTG.
      When maintenance is applied, the DFHDCTG group might be refreshed, overwriting your changes. Taking a backup avoids this problem.
  2. Define the intrapartition data set using job control statements.
    See Defining the intrapartition data set for details on how to do this step.
  3. Define the extrapartition data sets using job control statements.
    See Defining extrapartition data sets for details on how to do this step.
  4. To print CICS system messages on a local printer as they occur, use the transient data write-to-terminal sample program, DFH$TDWT.
    This sample program is supplied with the CICS in CICSTS56.CICS.SDFHLOAD and the assembler source is in CICSTS56.CICS.SDFHSAMP.