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Elixir
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Joined: 08 Feb 2009
Posts: 116
Location: CHENNAI/NEW JERSEY - INDIA/USA
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Hello,
thru rexx is it possible to before hand know the size to alocate for a ps/pds?
thanks! |
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enrico-sorichetti
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Joined: 14 Mar 2007
Posts: 10873
Location: italy
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YES ...
if You know the sizes of things that have to be contained in it
- number of members
- number of record
YES if You know the formulas and how to write REXX
otherwise the answer is NO/NO |
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Elixir
Active User
Joined: 08 Feb 2009
Posts: 116
Location: CHENNAI/NEW JERSEY - INDIA/USA
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1 CYL = 15 TRKS
1 TRK = 56, 664 BYTES
if you define the LRECL as 56664, then one record is stored in each track. |
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enrico-sorichetti
Superior Member
Joined: 14 Mar 2007
Posts: 10873
Location: italy
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| Quote: |
| f you define the LRECL as 56664, then one record is stored in each track. |
NO...
look at the manuals for the blksize and lrecl constraints
look at the stickies in the ispf part of the forums for a blocks per track calculator I wrote .
www.ibmmainframes.com/viewtopic.php?t=55037 |
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Pedro
Global Moderator
Joined: 01 Sep 2006
Posts: 2547
Location: Silicon Valley
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Besides the device geometry information, you really need to know how many members and how many records will be contained.
A somewhat lazy* approach is to allocate a large dataset and also specify the RELEASE parameter. After writing your records and closing the file, the unused space is released.
* I am somewhat lazy myself. |
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Robert Sample
Global Moderator
Joined: 06 Jun 2008
Posts: 8696
Location: Dubuque, Iowa, USA
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From the JCL Language Reference manual section 12.42.2 on LRECL in the DD statement, available at the Manuals link at the top of the page:
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The value of bytes is:
1 to 32,760 for non-VSAM data sets.
1 to 32,761 for VSAM key-sequenced (KS), entry-sequenced (ES), or relative record (RR) data sets. (LRECL does not apply to VSAM linear space, RECORG=LS, data sets.) |
Elixir, perhaps you want to revise this statement in light of the manual?
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| if you define the LRECL as 56664, then one record is stored in each track. |
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