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Hi Jeff
>Could someone give me some "benchmarks" defining good performance?
Performance is good when end-user expectations are met.
>What is a good benchmark for determining if a query is doing too many
>buffer reads, or too many disk reads? Is 10,000 buffer reads considered
>high, or is it 1,000,000? Or does it matter if, on the overall, things
>kick butt.
It really depends... eventually even 1 LIO is too much. This is the case = when it is not necessary to run the query!
Personally I usually give a look to the number of LIO per row. If this = value is smaller than 5 it is usually ok, if it is larger than 20 it is = normally bad. Everything in between should be analyzed.
>This is a half hour window during peak usage. Is anything way off?
More information is needed... e.g. how many CPU has your system?
HTH
Chris
-- http://www.freelists.org/webpage/oracle-lReceived on Wed Apr 20 2005 - 14:21:41 CDT