The P processing option
If the P processing option has been specified (with the PROCOPT parameter) in the PCB for your program, a GC status code is returned to your program whenever a command to retrieve or insert a segment causes a Unit of Work (UOW) boundary to be crossed.
Although crossing the UOW boundary probably has no particular significance for your
program, the GC status code indicates that this is a good time to issue a CHKP
command. The advantages of doing this are:
- Your position in the database is kept. Issuing a
CHKPnormally causes position in the database to be lost, and the application program has to reestablish position before it can resume processing. - Commit points occur at regular intervals.
When a GC status code is returned, no data is retrieved or inserted. In your program, you can either:
- Issue a
CHKPcommand, and resume database processing by reissuing the command that caused the GC status code. - Ignore the GC status code and resume database processing by reissuing the command that caused the status code.