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paul_seth55
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Joined: 09 Mar 2009
Posts: 3
Location: New York
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From what i understand, DATACLAS=COMPRES is used for DASD file to create a compressed version of file and to handle Volume issues for temporary file used in jobs. This parameter is also ignored when we provide other parameters DISP, SPACE, LRCEL, etc. This have no signigicance over TAPE files.
My question is if the Compressed DASD file is copied back to TAPE GDG version, will data be in compressed format or TAPE just consider it as a regular data and space for storage is based on the (number records+Record length+block size)?
I am working on MIPS optimization, where in 0th version Tape file is copied to DASD file with DATACLAS=COMPRES, which takes approximately 18M. The next Step creates +1st Tape version of same GDG where records from a VSAM file is copied. The final step appends the DASD created in First step into the +1 version, which only takes 3M. If i can use the 0th version in the final step, this can completly eliminate the 18M of CPU time. I just wanted to know in DATACLAS=COMPRESS have any significance.
Thanks in Advance for your reply. |
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dick scherrer
Moderator Emeritus
Joined: 23 Nov 2006
Posts: 19244
Location: Inside the Matrix
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Hello and welcome to the forum,
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| DATACLAS=COMPRES is used for DASD file to create a compressed version of file. . . |
I suspect this is something site-specific.
Suggest you speak with your storage management people for the most complete info. |
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expat
Global Moderator
Joined: 14 Mar 2007
Posts: 8797
Location: Welsh Wales
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| Quote: |
| My question is if the Compressed DASD file is copied back to TAPE GDG version, will data be in compressed format or TAPE just consider it as a regular data and space for storage is based on the (number records+Record length+block size)? |
That depends on the system and hardware defined compression parameters. |
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Anuj Dhawan
Superior Member
Joined: 22 Apr 2006
Posts: 6250
Location: Mumbai, India
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Hi Dick,
Pardon my small experience - I believe DATACLAS are alaways site-specific.. 
paul_seth55,
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| I just wanted to know in DATACLAS=COMPRESS have any significance. |
As an experiment, you might try with different "DATACLAS"es availabe at your end? If you have already tried, what was the result? |
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paul_seth55
New User
Joined: 09 Mar 2009
Posts: 3
Location: New York
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| Thanks everyone for the inputs. Let me check this information with the Storage admin! |
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