Portal | Manuals | References | Downloads | Info | Programs | JCLs | Master the Mainframes
IBM Mainframe Computers Forums Index
 
Register
 
IBM Mainframe Computers Forums Index Mainframe: Search IBM Mainframe Forum: FAQ Memberlist Usergroups Profile Log in to check your private messages Log in
 

 

How IMS knows what physical VSAM datasets to access

 
Post new topic   Reply to topic    IBMMAINFRAMES.com Support Forums -> IMS DB/DC
View previous topic :: :: View next topic  
Author Message
gautam79

New User


Joined: 30 Aug 2006
Posts: 11
Location: India

PostPosted: Fri Mar 09, 2007 4:22 pm    Post subject: How IMS knows what physical VSAM datasets to access
Reply with quote

Hi,

An IMS application program uses PSB to access a database. PSB has DBD name and it comes to know what database to go and access.

What i want to know is how does IMS comes to know, which physical dataset corresponds to a particular database?

Please try to explain in detail!!
Thanks
Back to top
View user's profile Send private message

Devzee

Active Member


Joined: 20 Jan 2007
Posts: 684
Location: Hollywood

PostPosted: Sat Mar 10, 2007 1:36 am    Post subject:
Reply with quote

We can tell the JOb to refer to Physical dataset by giving the corresponding DD name in the JCL.

//DBDNAME DD DSN=ACTUAL PHYSICAL Dataset

In some work sites there will be default physical dataset name allocation in that case you dont have to give the actual physical dataset name.
To use this default there should be some library like DYNALLIB in the JOBLIB statement of your job
Back to top
View user's profile Send private message
gautam79

New User


Joined: 30 Aug 2006
Posts: 11
Location: India

PostPosted: Mon Mar 12, 2007 10:43 am    Post subject:
Reply with quote

Thanks devzee, but in our case, we were using those DD names for our old JCLs, but when new version of IMS was implemented, after that we didnt require to use those DD names. The IMS would resolve those on its own.

Someone actually told me that RESLIB actually takes care of these. is that true?
Back to top
View user's profile Send private message
Devzee

Active Member


Joined: 20 Jan 2007
Posts: 684
Location: Hollywood

PostPosted: Tue Mar 13, 2007 10:49 am    Post subject:
Reply with quote

It really depends how your system and jcls are configured.

Actually RESLIB contains load modules for IMS, for DD names we use DYNALLIB in JOBLIB card.
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 -> IMS DB/DC All times are GMT + 6 Hours
Page 1 of 1

 

Search our Forum:

Similar Topics
Topic Author Forum Replies Posted
No new posts find RACF group for access to spooled... jzhardy JCL & VSAM 1 Mon May 08, 2017 11:46 am
No new posts VSAM Space Allocation mrgnndhmk JCL & VSAM 7 Sat Apr 22, 2017 12:42 am
This topic is locked: you cannot edit posts or make replies. SDSF multiple spool datasets extracte... PJAlarcon CLIST & REXX 1 Fri Apr 21, 2017 10:50 pm
No new posts Edit large number of datasets (QSAM) zh_lad TSO/ISPF 3 Tue Apr 04, 2017 6:08 pm
No new posts Updating a VSAM file with DISP=OLD sheersh JCL & VSAM 8 Tue Mar 14, 2017 6:14 pm


Facebook
Back to Top
 
Mainframe Wiki | Forum Rules | Bookmarks | Subscriptions | FAQ | Tutorials | Contact Us