MVSFORUMS.com

[vjkumk]

I have two questions.

there is a DD CARD in jcl as follows

//DFSVSAMP
1024,20
4096,20
8192,8
/*

1)Actually this jcl card is used to access a IMS database ,which consists of vsam clusters.So to access this IMS database they are giving buffer pool values ,For example ,what i understand is 1024,20 ,1024 ->control interval size is the value given while creating the vsam file ,so they are giving that value here, what is the 20 given for? and
why they are giving 3 buffer pool values.Since Control Interval size is only two(for base and index cluster)

2)I came to know that the maximum size of the VSAM cluster is 4GB.
It will be helpful to me ,if you give some info on OSAM Clusters and its maximum file size limit.


Thanks
vjkumk

[kolusu]

vjkumk,

Check this link which explains in detail about DFSVSMxx

http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/DFSISDG1/8.2.18?DT=20040903073414

Hope this helps...

Cheers

Kolusu
_________________
Kolusu
www.linkedin.com/in/kolusu

[Bithead]

These parameters define the VSAM buffer pools as follows:

CISIZE 1024 - 20 buffers
4096 - 20 buffers
8192 - 8 buffers

OSAM buffers are defined using th IOBF= parameter.

[ANIL SARATHY]

For information

To check buffer usage , include

//DFSSTAT DD SYSOUT=*.

this ddname will give number of different calls executed, % buffer usage.... Try this . to know more about IMS buffers
_________________
Anil Sarathy

[vjkumk]

Acutally the step is using a proc named IMSDG , i checked with adding //DFSSTAT DD SYSOUT=*.It is not writing any information in the sysout of DFSSTAT.