Why more than 1 PSB??

ap_mainframes · Posted: Thu Jul 03, 2008 6:40 pm Post subject: Why more than 1 PSB??

Hi,

Can anybody explain why and when we would need to create more than one PSB for a DB ??

Thanks,
ap_mainframes

Bharath Nadipally · New User Joined: 24 Jun 2008 Posts: 20 Location: Hyderabad

PSB is a logical collection of databases which an application(program) will use. A database(or segments) can be used by n number of programs, so a database can be used by n number of PSB's.

Sandy Zimmer · Posted: Thu Jul 03, 2008 8:47 pm Post subject:

Expanding on what Bharath had to say. Most shop standards dictate that each application program have their very own PSB - unique to what that application will be doing. The PSB should also have the same name as the program. Global PSBs are NOT a good idea at all!

Mahendran3784 · New User Joined: 04 May 2007 Posts: 12 Location: INDIA

what are the expected problems of having Global PSBs for various programs?

Sandy Zimmer · Posted: Wed Jul 16, 2008 12:05 am Post subject:

Well, CONTENTION for number 1. Why should an application that only needs 1 database use a PSB accessing 20? A PSB that gets STOPPED for any reason will impact a multitude of application. As I've said, most fast transaction processing installations INSIST that a PSB be unique to a particular program.

Mahendran3784 · New User Joined: 04 May 2007 Posts: 12 Location: INDIA

Thanks Sandy.
Is it that contention of DBs used in the PSB? And what are the scenarios a PSB get STOPPED?

- Mahendran[/quote]

Sandy Zimmer · Posted: Wed Jul 16, 2008 3:48 pm Post subject:

Normally a PSB gets stopped when there is an abend. Please just think this thru - 1 PSB per program. Think about how easy this is. Aside from the contention issues, etc, your linkage and entry statements will only contain the databases that you need. A PSB is a program specification block - exactly that - it is not based on a particular database. It is based on an application.

dick scherrer · Posted: Wed Jul 16, 2008 9:19 pm Post subject:

Hello,

A single psb per program will also reduce resources needed for execution of each program.

Another place a single psb per program can help is impact analysis.

FWIW. . .