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Need help regarding the UNIT parameter.


IBM Mainframe Forums -> DFSORT/ICETOOL
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anandmsteds

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Joined: 07 Mar 2007
Posts: 8
Location: Mumbai

PostPosted: Wed Oct 14, 2009 4:59 pm
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Hello All,

I have the below requirement which requires experts help.

Requirement:

1. I have 15 GDG bases (each base contains 1 generation). Each generation contains 1 or 2 millions of records in it. And the parameters used for each generation is as below:
// DISP=(NEW,CATLG,DELETE),
// BUFNO=14,
// DCB=(GDG.MODEL,BLKSIZE=27993,LRECL=903,RECFM=FBA),
// LABEL=RETPD=7,
// UNIT=(CTAPE,,DEFER)

2. Now I need to concatenate all the 25 generations and need to sort concatenated file.
3. Later the sorted output file will be given as input to another program which will produce the desired output.

Questions:

1. For SORTOUT file, can I use the UNIT parameter as CTAPE itself? Will it hold the entire 15 generations data in it?
2. How many work files I need to use while sorting. And what could be the SPACE parameter I need to use for the work files?

Thanks
Anand
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dick scherrer

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Joined: 23 Nov 2006
Posts: 19244
Location: Inside the Matrix

PostPosted: Wed Oct 14, 2009 7:48 pm
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Hello,

Are the individual files already in the same sequence as the combined file will be? "Merge" may be a better choice than "Sort". . .

As far as the output UNIT, suggest you talk with your storage management people. If you specify some kind of "tape" unit and the amount of output is more than a single "tape" volume will hold, additional volumes will be automatically written up to the volume limit on your system (again, your storage management people will know this).
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Bill Dennis

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Joined: 17 Aug 2007
Posts: 562
Location: Iowa, USA

PostPosted: Wed Oct 14, 2009 8:59 pm
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Determining the SPACE needed for your 15 (or 25?) files is very basic.

The SPACE for workfiles will be the number of records * LRECL (bytes)and then reduced to CYLs. If these are tapes, you might be able to get the BLOCK count of each volume from the TMS and divide by two (2 blks per trk) for number of tracks.

Add some extra or allow secondary allocations.

Divide this across the number of SORTWKxx files to get size of each.
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Frank Yaeger

DFSORT Developer


Joined: 15 Feb 2005
Posts: 7129
Location: San Jose, CA

PostPosted: Wed Oct 14, 2009 10:22 pm
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Quote:
How many work files I need to use while sorting. And what could be the SPACE parameter I need to use for the work files?


Don't specify SORTWKdd DD statements. Let DFSORT allocate the work data sets dynamically. If your installation default for the number of work data sets does not work, you can specify:

Code:

//DFSPARM DD *
  OPTION DYNALLOC=(,n)


where n is 8, 16, 32 or whatever works.
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