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 we calculate the BLKSIZE for Variable Block

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

New User


Joined: 02 Jun 2006
Posts: 49

PostPosted: Wed Aug 30, 2006 8:59 am    Post subject: How can we calculate the BLKSIZE for Variable Block
Reply with quote

Hi all,

I have small doubt in the DCB Parameter. Any one of you please clarify the same?


Fixed Block
-------------
// RECFM=FB,LRECL=80,BLKSIZE=9040
This dataset will have fixed length records with a length of 80. There will be 113 records of data per block.

BLKSIZE/LRECL = 9040/80 = 113 records of data per block

Note: Multiple's of LRECL is BLKSIZE (80*113=9040)

Variable Block
--------------
// RECFM=VB,LRECL=255,BLKSIZE=3120
This dataset will have variable length records with a maximum of 255 characters. The blocksize of the dataset will be 3120.


Here, I am unable to understand this BLKSIZE concept. Here, BLKSIZE =3120 (But, it is not multiple's of 255). How can we calculate the BLKSIZE for Variable Block? Could you please let me know the same?
Back to top
View user's profile Send private message

priyesh.agrawal

Senior Member


Joined: 28 Mar 2005
Posts: 1452
Location: Chicago, IL

PostPosted: Wed Aug 30, 2006 10:19 am    Post subject: Re: Doubt in DCB Parameter?
Reply with quote

Husna,

Quote:
I am unable to understand this BLKSIZE concept. Here, BLKSIZE =3120 (But, it is not multiple's of 255).

In case of VB, its not necessary for BLKSIZE to be a multiple of LRCEL.
It should be either same as or greater than LRECL in case of VB recs.
Back to top
View user's profile Send private message
Husna

New User


Joined: 02 Jun 2006
Posts: 49

PostPosted: Wed Aug 30, 2006 10:27 am    Post subject:
Reply with quote

Hi Priyesh,

Thanks...
Back to top
View user's profile Send private message
Dariusz
Warnings : 1

New User


Joined: 11 Aug 2005
Posts: 27
Location: POLAND

PostPosted: Wed Aug 30, 2006 3:45 pm    Post subject: VB records.
Reply with quote

Hi.
For VB records minimal BLKSIZE must be equal LRECL+4.
Regards.
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 Allocate dataset withour BLKSIZE Susanta CLIST & REXX 2 Thu Sep 22, 2016 11:51 am
No new posts SORT Block of records girishb2 DFSORT/ICETOOL 12 Thu Sep 15, 2016 8:58 am
No new posts Format to pipe delimited with variabl... pshongal SYNCSORT 6 Wed Sep 14, 2016 2:48 pm
No new posts How to calculate an specific transact... lind sh CICS 2 Tue Sep 13, 2016 9:20 pm
No new posts Variable for cursor names ravikumar15 DB2 5 Sun Jul 17, 2016 7:08 am


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