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Pandora-Box
Global Moderator
Joined: 07 Sep 2006 Posts: 1592 Location: Andromeda Galaxy
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Hi,
We had changed RUNSTATS & REORG which were executing in different steps to one single step in order to reduce the CPU time but inspite of doing that there is not much change?
Experts need your suggesion and advice on the same.
Thanks in advance. |
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enrico-sorichetti
Superior Member
Joined: 14 Mar 2007 Posts: 10872 Location: italy
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Why would You think that running as a single step would reduce resource usage ?
the only things that get executed once instead of two are
JCL related processing
converter/interpreter/jes stuff
allocation
program initialization
DB2 connect
program fetch
relly nothing worth the trouble of restructuring the process |
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Pandora-Box
Global Moderator
Joined: 07 Sep 2006 Posts: 1592 Location: Andromeda Galaxy
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My assumption is We wont be having too many hits to DB2 by having something like one below where we execute them in one single step
Code: |
REORG TABLESPACE DBNAME.TSNAME
PART 01 LOG NO KEEPDICTIONARY
STATISTICS TABLE (ALL) UPDATE (ALL)
INDEX(INDEX1)
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My assumption is given the code in one above format happens parallely then in two different steps.
Correct me if i am wrong Enrico
Thanks in advance |
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dick scherrer
Moderator Emeritus
Joined: 23 Nov 2006 Posts: 19244 Location: Inside the Matrix
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Hello,
Quote: |
My assumption is given the code in one above format happens parallely then in two different steps. |
Quote: |
Correct me if i am wrong |
No, they happen serially, rather than in parallel. Note the start and stop times of the 2 processes. |
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Pandora-Box
Global Moderator
Joined: 07 Sep 2006 Posts: 1592 Location: Andromeda Galaxy
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Thanks dick.
Is there any way to reduce the CPU & ELAPSED time consumed? |
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expat
Global Moderator
Joined: 14 Mar 2007 Posts: 8797 Location: Welsh Wales
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Whether in one step or two steps, the amount of work being processed is the same. Therefor the amount of processor resource consumed will be the same.
With the details given bt Enrico, you could expect to say maybe a millisecond or two of CPU.
Reducing elapsed time depends on a whole lot of different factors, often where many are not under your own control. |
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Pandora-Box
Global Moderator
Joined: 07 Sep 2006 Posts: 1592 Location: Andromeda Galaxy
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Got that Expat thanks for your advice |
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dick scherrer
Moderator Emeritus
Joined: 23 Nov 2006 Posts: 19244 Location: Inside the Matrix
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Hello,
Quote: |
Is there any way to reduce the CPU & ELAPSED time consumed |
Probably not the cpu time. Possibly the elapsed time by changing when these are run (an empty machine) or installing faster equipment. |
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