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DB2 Utility performance

 
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Pandora-Box

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PostPosted: Sat Aug 08, 2009 2:49 pm    Post subject: DB2 Utility performance
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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

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PostPosted: Sat Aug 08, 2009 2:59 pm    Post subject: Reply to: DB2 Utility performance
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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

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PostPosted: Sat Aug 08, 2009 4:15 pm    Post subject:
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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)



My assumption is given the code in one above format happens parallely then in two different steps.

Correct me if i am wrong Enrico icon_redface.gif


Thanks in advance
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dick scherrer

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PostPosted: Sun Aug 09, 2009 12:33 am    Post subject:
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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

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PostPosted: Wed Aug 12, 2009 4:13 pm    Post subject:
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Thanks dick.

Is there any way to reduce the CPU & ELAPSED time consumed?
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expat

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PostPosted: Wed Aug 12, 2009 4:25 pm    Post subject:
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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

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PostPosted: Wed Aug 12, 2009 4:35 pm    Post subject:
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Got that Expat thanks for your advice icon_smile.gif
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dick scherrer

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PostPosted: Wed Aug 12, 2009 7:45 pm    Post subject:
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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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