Actually I thought the same thing about reading all the input datasets
so I tried an experiment on it.  I copied 4 datasets to 2 new packs
(about 4000 cylinders of MXG monthly PDB datasets) and the copy took
about 10 minutes wall time and consumed about 10000 EXCPs to create
these 4 datasets.  I then ran the DUMP with the output to DD DUMMY and
the entire thing consumed 161 EXCPs and ran in 1 second wall clock time.
So apparently DFDSS is smart enough to not copy data that is going to DD
DUMMY.  

Rex

-----Original Message-----
From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On
Behalf Of Joel C. Ewing
Sent: Monday, May 01, 2006 10:28 PM
To: IBM-MAIN@BAMA.UA.EDU
Subject: Re: ISPF Option 3.4 and System Search for all Files with
A*.NC2.*


Glen.Gasior wrote:
> I would not assume the search done by ISPF is the same as the search 
> done by DFSMSDSS. ISPF will search through all catalogs and not limit 
> itself to the standard catalog search if there is a wildcard in the 
> first hlq. I do not know about DFSMSDSS. You may need to know the 
> details of each search algorithm to know if they are equivalent.
> 

Several potential problems with the suggested DFDSS approach:
        DFDSS will only find datasets on primary volumes - any datasets 
migrated to ML1 or ML2 will be ignored and not deleted.
        Although the indicated job will not actually write any data to
the 
DUMMY output dataset, the DFDSS DUMP will still incur the overhead of 
reading through all data of the datasets being deleted.
        The TOL(ENQF) should become a problem (delete failure) when it
is time 
for the DELETE to occur if any other address space has the dataset
enqueued.

If there are not that many datasets and migration is a possibility, I 
would be tempted to look for some BATCH REXX approach with LISTC and 
DEL, which would handle migrated datasets.  If there were 5K+ datasets 
involved, using the Catalog Search Interface to identify the datasets 
rather than LISTC would take more work but would be considerably more 
efficient.




-- 
Joel C. Ewing, Fort Smith, AR        [EMAIL PROTECTED]

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