Portal | Manuals | References | Downloads | Info | Programs | JCLs | Mainframe wiki | Quick Ref
IBM Mainframe Computers Forums Index
 
Register
 
IBM Mainframe Computers Forums Index Mainframe: Search IBM Mainframe Forum: FAQ Memberlist Profile Log in to check your private messages Log in
 
How to manage VSAM file update conflict and corruption

 
Post new topic   Reply to topic    IBMMAINFRAMES.com Support Forums -> JCL & VSAM
View previous topic :: :: View next topic  
Author Message
ocjohnh

New User


Joined: 19 Sep 2007
Posts: 3
Location: hong kong

PostPosted: Sat Jul 21, 2018 6:04 am    Post subject: How to manage VSAM file update conflict and corruption
Reply with quote

Hi, I am a rookie for VSAM.

We are going to built a self-developed VSAM KSDS file with a few AIX,
there are chances that records in the file are online-queried by in-house TSO users and updated by batch jobs at the same time.

The records for online query might be acquired by repro utility in TSO background and then they are plugged into an ISPF table for online display. On the other hands update batch jobs could be COBOL, EASYTRIEVE OR simply a IDCAMS REPRO (yet to be confirmed).

In this situation I wonder if share-option is the best way to manage access conflict between users and batch jobs. Also should every batch job need to make a copy of the VSAM file by repro before update?
that seems a little bit clumsy for recovery. How often would a VSAM file get corrupt !?

Am I getting anything wrong !? hope for helps
Back to top
View user's profile Send private message

Robert Sample

Global Moderator


Joined: 06 Jun 2008
Posts: 8410
Location: Dubuque, Iowa, USA

PostPosted: Sat Jul 21, 2018 7:29 am    Post subject: Reply to: How to manage VSAM file update conflict and corruption
Reply with quote

Quote:
I wonder if share-option is the best way to manage access conflict between users and batch jobs.
Actually, the shareoption setting is the ONLY way to manage access conflict -- you set the shareoption values depending upon what you are trying to do. And, depending upon the selected values, you may have to implement ENQUEUE / DEQUEUE logic in each program using the VSAM data set.
Quote:
How often would a VSAM file get corrupt !?
Depending upon the way it is defined, and how it is accessed as well as the enqueue / dequeue facility used, the answer to this question could be never, or once in a while, or once a year, or once a month, or once a week, or once a day, or once an hour, or pretty much every time it is accessed.

And it is a data set, not a file -- z/OS has files on tape or in Unix System Services only; every disk data set (and VSAM is on disk) is a data set not a file.

If you have not downloaded / read the Redbook VSAM Demystified you need to do so -- NOW! It should be required reading for every VSAM rookie.
Back to top
View user's profile Send private message
ocjohnh

New User


Joined: 19 Sep 2007
Posts: 3
Location: hong kong

PostPosted: Sat Jul 21, 2018 4:34 pm    Post subject:
Reply with quote

thx for the help.. icon_biggrin.gif
Back to top
View user's profile Send private message
View previous topic :: :: View next topic  
Post new topic   Reply to topic    IBMMAINFRAMES.com Support Forums -> JCL & VSAM All times are GMT + 6 Hours
Page 1 of 1

 

Search our Forum:

Similar Topics
Topic Author Forum Replies Posted
No new posts Transferring file to Mainframes Shinoj Vijayakumar IBM Tools 3 Thu Dec 06, 2018 2:35 pm
No new posts Convert VBA file to FB! Vignesh Sid SYNCSORT 5 Mon Dec 03, 2018 1:27 pm
No new posts Another 39 File Status on VB file socker_dad COBOL Programming 5 Tue Nov 27, 2018 6:11 am
No new posts How to handle different file length b... javen777 DFSORT/ICETOOL 15 Mon Nov 26, 2018 12:13 pm
No new posts COBOL file declaration jithinraghavan COBOL Programming 2 Fri Nov 16, 2018 10:54 pm

Facebook
Back to Top
 
Job Vacancies | Forum Rules | Bookmarks | Subscriptions | FAQ | Polls | Contact Us