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Time taken by a DB2 Query increases

 
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Geethi

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Joined: 03 Mar 2007
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PostPosted: Tue Jul 03, 2007 2:37 am    Post subject: Time taken by a DB2 Query increases
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Hi,

I am having a SELECT statement with DISTINCT, GROUP BY, CASE clauses. This is used to create a report. But each time I run the query, the total time taken by it, is increased. Please somebody tell me why this happen so.

Thanks in advance,
Geethi
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dick scherrer

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Joined: 23 Nov 2006
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PostPosted: Tue Jul 03, 2007 2:43 am    Post subject:
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Hello,

Please post your full query, the definition of the table(s) referenced, approximately how many rows are in each table, and the growth rate for the tables. Do the tables have purge criteria (i.e. are rows regularly deleted or will this continue to grow with no restraint)?

Did this suddenly happen or has the time been increasing over some period of time.
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Geethi

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PostPosted: Tue Jul 03, 2007 2:55 am    Post subject: Re: Time taken by a DB2 Query increases
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So far the query was taking less than 5 minutes of time. Suddenly it started taking 380 sec, 480 sec, 720 sec and so on.
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dick scherrer

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PostPosted: Tue Jul 03, 2007 3:46 am    Post subject:
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Hello,

Well, 5 min is 300 seconds, so it is not that big a jumo to 380. It sounds like the run time may increase exponentially rather than linear.

If you post the info requested earlier, we may be able to offer suggestions.
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