What are GSAM Files? Why do we need them?

RDBMS from IBM and IBM's Hierarchical DBMS and Transaction Manager (IMS DC).
Post Reply
Om Prakash
Registered Member
Posts: 22
Joined: Tue Jul 23, 2013 3:22 pm

What are GSAM Files? Why do we need them?

Post by Om Prakash »

Hello,

What are GSAM Files? Why do we need them? Can someone please help me with dome document available for GSAM files? Which can give basics about it.

Thanks,
Manoj
Registered Member
Posts: 33
Joined: Wed Jul 17, 2013 9:10 am

Re: What are GSAM Files? Why do we need them?

Post by Manoj »

As much as I know - GSAM files are used when you need check-point restart in your program...
User avatar
Anuj Dhawan
Founder
Posts: 2816
Joined: Sun Apr 21, 2013 7:40 pm
Location: Mumbai, India
Contact:
India

Re: What are GSAM Files? Why do we need them?

Post by Anuj Dhawan »

GSAM stands for Generalized Sequential Access Method. I might sound a bit picky, however, there is nothing called as "GSAM Files" technically. They are "GSAM data-sets". GSAM data-sets can be considered as a "single occurence" of a IMS database. As DL/I was written as the main language for IMS DB, when an IMS program uses a GSAM data set, the program treats it like a "sequential nonhierarchic database". From that prespective, GSAM has no segments, no keys, and no parentage and that's obvious.

As Manoj said, GSAM can be used for check-point restart, however, your program must use symbolic CHKP and XRST calls if it uses GSAM. Basic CHKP calls cannot checkpoint GSAM databases.

Here is more on how to process GSAM in your program: Processing GSAM Databases.
Thanks,
Anuj

Disclaimer: My comments on this website are my own and do not represent the opinions or suggestions of any other person or business entity, in any way.
Om Prakash
Registered Member
Posts: 22
Joined: Tue Jul 23, 2013 3:22 pm

Re: What are GSAM Files? Why do we need them?

Post by Om Prakash »

Thankyou Anuj.
Post Reply

Create an account or sign in to join the discussion

You need to be a member in order to post a reply

Create an account

Not a member? register to join our community
Members can start their own topics & subscribe to topics
It’s free and only takes a minute

Register

Sign in

Return to “IBM DB2 and IMS DB/DC”