Articles from hotsos
I don't have any specific question , but just wanted to know if anyone has read these articles..
I was reading asktom as usual and saw a link reference to
http://www.hotsos.com website.. this site is run by Cary Millsap who used to be in Oracle...and the memebership is free.
I read 3 interesting articles on this web site and all what I knew about Oracle seems to be wrong now...
1. When to Use an Index
2. Why 99% Database Buffer Cache Hit Ratio is NOT Ok
3. Performance Management: Myths
has any one read these articles. Whats your openion ?
Well yes..carry and his team is terrific..i especially liked the case studies he has provided..but i dont full agree on all points for example one one of them he says somethin like this
There was a batch job running and it used to take hours together...and we suggested that the batch job be run on the server itself..and use ipc instead of tcp/ip but alas on investigation we found that the batch job was already running on the server and it was using ipc had it been using tcp it would have been slower..
well i dont agree with this stuff as all the operating systems that i know off are smarter the kernels are intelligent enough to direct traffic to the loopback adapter when they know it meant for the local interface 127.0.0.1 and direct it to the ethernet card when the traffic is meant for some other ip..so in this case using ipc or tpc would noty have made any difference..
But on most part i would agree with carry and his team..about index useage..and not to format the trace file with tkprof rather then interpret and read the raw trace file..or use sparky to to read the trace file..but the tkprof utility supplied with 9i is much better..
and if you are on 9i i think you can happily use tkprof before that nope..
one last thing..tuning is developed by practise and experience..which carry gained while being on many customer sites..since he penns down his experiences those articles and case studies make a interesting read
I agree with them, especially about the BUFFER_CACHE % Ratios, I think there is an article on S.A.M.E there also (somewhere).
OCP 8i, 9i DBA
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