At one time there was a component called Actual Block Processor that was used 
both by VSAM and paging, and the paging data sets were CI format.  I have no 
idea how much of that, if any, remains in z/OS, but essentially my question was 
whether pages were now stored in 4 KiB physical records.


--
Shmuel (Seymour J.) Metz
http://mason.gmu.edu/~smetz3
עַם יִשְׂרָאֵל חַי



________________________________________
From: IBM Mainframe Assembler List <[email protected]> on behalf 
of Bob Raicer <[email protected]>
Sent: Monday, November 13, 2023 2:14 PM
To: [email protected]
Subject: Re: Is True Skip-Sequential Processing Possible with RECFM=FB,DSORG=PS?

A PDSE is essentially a form of VSAM Linear, where the physical data
set is a collection of 4K-byte blocks.  It does not have the notion
of CA's and CI's like other VSAM data sets.  The notion of BLKSIZE
is synthesized and mapped onto the internal PDSE structures; the
BLKSIZE value is not the physical unit of transfer size as is the
typical case for a traditional Physical Sequential data set.

Here is a URL for a SHARE presentation that provides a nice
explanation of how a PDSE is put together:

https://share.confex.com/share/124/webprogram/Handout/Session16956/PDSE%20Nuts%20and%20Bolts.pdf

Bob

On 2023-11-13 7:48 AM, Seymour J Metz wrote:
>
> Does anybody know whether CI size = block size for PDSE and zFS (linear) data 
> sets? VSAM used to use multiple blocks for a CI.
>
>
>

Reply via email to