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 can one differentiate between a flat file and a VSAM

 
Post new topic   Reply to topic    IBMMAINFRAMES.com Support Forums -> HomeWorks & Requests
View previous topic :: :: View next topic  
Author Message
bh

New User


Joined: 19 Mar 2006
Posts: 26
Location: India

PostPosted: Thu May 24, 2007 4:58 pm    Post subject: How can one differentiate between a flat file and a VSAM
Reply with quote

Hi,

How can one differentiate between a flat file and a VSAM file being used in a COBOL program ?


Regards,
gp
Back to top
View user's profile Send private message

William Thompson

Global Moderator


Joined: 18 Nov 2006
Posts: 3158
Location: Tucson AZ

PostPosted: Thu May 24, 2007 6:08 pm    Post subject:
Reply with quote

Isn't a different SELECT specification required?
Back to top
View user's profile Send private message
pingte

Active User


Joined: 03 Dec 2005
Posts: 120
Location: india

PostPosted: Thu May 31, 2007 2:04 pm    Post subject:
Reply with quote

VSAM will have 2 components- data and index. This will be 2 separate files associated with the main file.
Flat file has no such components.
Back to top
View user's profile Send private message
expat

Global Moderator


Joined: 14 Mar 2007
Posts: 8593
Location: Back in jolly old England

PostPosted: Thu May 31, 2007 2:45 pm    Post subject:
Reply with quote

Quote:
VSAM will have 2 components- data and index.

Where is the index component of an ESDS / RRDS ?
Also an ESDS can have an associated AIX and PATH !
Back to top
View user's profile Send private message
pingte

Active User


Joined: 03 Dec 2005
Posts: 120
Location: india

PostPosted: Thu May 31, 2007 2:57 pm    Post subject:
Reply with quote

KSDS will have data and index component..

Also AIX and PATH are for Alternate Cluster. It can be there for KSDS.
Back to top
View user's profile Send private message
donevin

New User


Joined: 07 Jun 2005
Posts: 70
Location: South Africa

PostPosted: Thu May 31, 2007 4:37 pm    Post subject:
Reply with quote

As William said a different slect statement is required. For flat files access mode and organization must be sequential. For relative record files, organization is relative, access mode can be sequential, random or dynamic and the same goes for key-sequential files where access mode is concerned. For key-sequential files organization is indexed and a record key must be declared. For RR files a relative key must be declared. This is off of the top of my head but should make the differences in the select statement clearer.
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 -> HomeWorks & Requests All times are GMT + 6 Hours
Page 1 of 1

 

Search our Forum:

Similar Topics
Topic Author Forum Replies Posted
No new posts Fail to change physical VSAM filename... jacobdng CICS 0 Fri Jan 20, 2017 12:36 pm
No new posts SORTJOIN - Copy Matched and Unmatched... Steve Ironmonger DFSORT/ICETOOL 5 Tue Jan 17, 2017 4:26 pm
No new posts how to recover an uncataloged VSAM da... archanamuthukrishnan All Other Mainframe Topics 3 Wed Jan 11, 2017 6:18 pm
No new posts Underlying DB2 VSAM LDS - SMF recording vasanthz All Other Mainframe Topics 6 Thu Jan 05, 2017 4:20 am
No new posts Copy RECFM =VB TO FB file with RECL =... sahil41352 DFSORT/ICETOOL 3 Wed Dec 28, 2016 11:29 pm


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