CICS provides a programming interface to JES (Job entry subsystem) of MVS. The JES interface allows CICS applications to create and retrieve spool files. To use the JES interface, you should have the DHFSIT SPOOL parameter set to YES (DFHSIT SPOOL=YES) in CICS installation.
CICS provides the 4 SPOOL interface commands that are used in a job submission. They are as follows.
- SPOOLOPEN (INPUT|OUTPUT)
- SPOOLREAD
- SPOOLWRITE
- SPOOLCLOSE
All-access to a JES spool file must be completed in one task in a CICS program. It should be noted that any job that processes the data sets for more than 1000 records for I/O is likely to have a performance effect on the rest of CICS.
