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
 

 

wants material on gsam db

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

New User


Joined: 30 Jul 2004
Posts: 95

PostPosted: Tue Apr 19, 2005 8:14 pm    Post subject: wants material on gsam db
Reply with quote

hi all,

i want some information regarding gsam db

thanks & regards
ksivapradeep
Back to top
View user's profile Send private message

Vijay Bhadauria

New User


Joined: 28 Mar 2005
Posts: 8

PostPosted: Wed Apr 20, 2005 10:06 am    Post subject: Re: wants material on gsam db
Reply with quote

Hi Ksivapradeep,

GSAM databases are sequentially organized databases designed to be compatible with MVS data sets. GSAM databases can be on a data set previously created or one later accessed by the MVS access methods VSAM or QSAM/BSAM. GSAM data sets can use fixed-length or variable-length records when VSAM is used, or fixed-length, variable-length or undefined-length records when QSAM/BSAM is used. If VSAM is used to process a GSAM database, the VSAM data set must be entry sequenced and on a DASD. If QSAM/BSAM is used, the physical sequential (DSORG=PS) data set can be on a DASD, tape, or unit record device. Because GSAM is designed to be compatible with MVS data sets, the GSAM database has no hierarchy, database records, segments, or keys.

GSAM databases are loaded in the order in which you present records to the load program. You cannot issue DLET and REPL calls against GSAM databases; however, you can issue ISRT calls after the database is loaded but only to add records to the end of the data set. Records are not randomly added to a GSAM data set.

GSAM database is basically used for Chekpointing/Restart. IMS takes cares of correct repositioning of the GSAM database at the time of restart.

So in order to use a sequential (MVS) file as GSAM file(IMS), you need to create DBD and have to make entry in PSB used for the program using GSMA file.


Cheers,
Vijay
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 GSAM from IMS online Appu IMS DB/DC 4 Tue Dec 29, 2015 6:25 pm
No new posts GSAM conversion in IMS DB to DB2 migr... asukumar IMS DB/DC 2 Tue Feb 18, 2014 1:12 pm
No new posts Need Comparex Study Material daga.aditya JCL & VSAM 3 Mon Dec 02, 2013 11:59 pm
No new posts Doubt on deletion of the record from ... hemanthj642 IMS DB/DC 2 Fri Dec 02, 2011 3:53 pm
No new posts Check point/Restart logic for GSAM files hemanthj642 IMS DB/DC 5 Mon Nov 07, 2011 5:04 pm


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