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monisiqbal 119 posts Joined 07/09
02 May 2008
TotalCpuTime and response time

We calculate response time as: (FirstRespTime - StartTime) in DBQLogTbl. This value is sometimes big with 0 in TotalCPUTime.How can this be possible?Doesn't the difference between FirstRespTime and StartTime signify that the query has brought some impact on the Teradata system and some CPU consumption must have been made?

Adeel Chaudhry 773 posts Joined 04/08
21 May 2008

No, because the task/query may require 0.001 micro seconds of a CPU time but may have to wait for 1 second before getting that CPU time, there surely is a difference between the two!Regards,Adeel

-- If you are stuck at something .... consider it an opportunity to think anew.

monisiqbal 119 posts Joined 07/09
01 Jul 2008

Your explanation about Response time makes sense.But I can see such entries (with 0 CPU time) with TotalIOCount > 0. Does this look right?

Adeel Chaudhry 773 posts Joined 04/08
01 Jul 2008

DBMS may be using caching, it may not be doing an actual disk I/O, and it may also be due to rounding-off errors.I guess the best answer of CPU time, I/O time etc can only be given by DBMS itself.Regards,Adeel

-- If you are stuck at something .... consider it an opportunity to think anew.

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