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Re: *Measuring sql performance (elapsed time and scalability) by number of logical reads

From: Radoulov, Dimitre <cichomitiko_at_gmail.com>
Date: Tue, 2 May 2006 23:15:17 +0200
Message-ID: <00b101c66e2d$84f72190$3c08310a@MPILA9>


[...]
> The second is IFFS with 610 LIO in 72513 us.
> Total is 1523 LIO..... AND 223005 us. Not 83118 us, right? Looks like
> we've found ~140 msec. And those 140 msec are not just hash value
> calculation, but also memory management (chunk allocation) in PGA,
> probably growing PGA itself etc.
>
> Also, as somebody already mentioned, LIO time can vary significantly.
> 10605/913 ~= 11.6 us and 72513/610 ~= 119 us. The length of hash chains
> may count, for example. Well, on quiet instance that might be row
> processing time inside the block as well and not only the time to pin the
> buffer.

[...]

Thank you for your time and valuable feedback. Anyway, correct me if I'm wrong, but I would expect those to be considered wait events, not service time.

Regards,
Dimitre

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Received on Tue May 02 2006 - 16:15:17 CDT

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