Primary and Secondary Space allocation for a flat SYSDA file

Soumya Roy · New User Joined: 19 Feb 2009 Posts: 10 Location: Bangalore

Hi all,

Can anyone suggest what is the exact calculation behind the primary and secondary allocation for a flat disk file.
Suppose we decalre a space parameter like :
SPACE=(CYL,(250,99),RLSE)
How the allocation will happen in this case both for Primary and secondary.

And how the RLSE work... I mean will it release only the unused primary cyllinders or the unused secondary cyllinders or both.

Thanks.

expat · Posted: Thu Jun 18, 2009 1:12 pm

1) Have you read the JCL Reference manual - easily reached by using the "IBM Manuals" button at the top of each page.

2) Have you searched the forum for similar topics.

Robert Sample · Posted: Thu Jun 18, 2009 5:04 pm

Primary: figure out how much space you need to hold the records that are going to be put into the file. That is a good minimum primary value.

Secondary: Figure out how much growth in the record count over time there will be, or what the peak processing requires, or find some other measure to determine how much additional space is needed. Use that for the secondary.