Think the default is CILOCK=NO, so if you override it with CILOCK=YES you might find it in your overrides, otherwise it should already be set. It is documented in the CICS Systems Definition Guide. I don't think it made the original TS 2.2 manuals but APAR PQ74971 provided documentation if you don't have the latest manuals. It is in the 2.2.7.473u release of the CICS Information Center I'm using.

Richard Bohonsky Perot Systems Corporation

-----Original Message----- From: CICS List [mailto:CICS-L@LISTSERV.UGA.EDU] On Behalf Of Flores, Michael J. Sent: Tuesday, January 18, 2005 6:12 PM To: CICS-L@LISTSERV.UGA.EDU Subject: Re: Simultaneously updating a VSAM file from two tasks using 2 different filenames

Didn't see this SIT parameter for 2.2. Are you sure it's available for TS 2.2? What VSAM SHR option are you using for the two files?

-----Original Message----- From: CICS List [mailto:CICS-L@LISTSERV.UGA.EDU]On Behalf Of Bohonsky, Richard E. Sent: Tuesday, January 18, 2005 4:18 PM To: CICS-L@LISTSERV.UGA.EDU Subject: Re: Simultaneously updating a VSAM file from two tasks using 2 different filenames

Are you at CICS TS 2.2 or later? Do you have CILOCK=NO in the SIT? If you do, shouldn't see the lock held until REWRITE, just until the READ for UPDATE is finished.

Richard Bohonsky Perot Systems Corporation

-----Original Message----- From: CICS List [mailto:CICS-L@LISTSERV.UGA.EDU] On Behalf Of John Krew Sent: Tuesday, January 18, 2005 4:37 PM To: CICS-L@LISTSERV.UGA.EDU Subject: Simultaneously updating a VSAM file from two tasks using 2 different filenames

I tried reading and updating the same VSAM file from two different CICS tasks using CECI. The catch is that the VSAM file is defined twice in the CSD definitions. One filename references the physical VSAM dataset with user-journalling defined, while the second filename references the same dataset with user-journalling not defined.

One task read filename1 with update and then rewrote the record. The other task read filename 2 (same physical VSAM file), reading for update a *different* record (different key) but probably in the same control interval.

What happened is that the second read waits for the first read/update transaction to finish. As soon as the REWRITE operation ends, the second task stops waiting and its READ with UPDATE is executed. In other words, the behavior I would expect if the *same* filename was used by the two tasks.

The upshot seems to be that two CICS tasks can simultaneously update the same physical VSAM file via two different logical file names, the only apparent conflict being the wait one causes the other when they both go after a record in the same control interval.

This behavior is important to us as it would allow us to prevent CDC data (recorded on user journals) from being bounced back and forth between source and target files (databases) in an infinite loop.

Can someone confirm my conclusions either from their experience or from IBM documentation?

Thanks, John Krew