Re: testing memory parameters
Date: Mon, 17 Mar 2008 07:30:49 -0400
Message-ID: <64733cF2ao6lcU1@mid.individual.net>
> Below what value is BCHR "bad"?
In DB2 I treat any OLTP app with less than 90% hit ratio as troubled.
Anything less than 80% I'd call a mess requiring some serious explanation.
> Above what value is BCHR "good"?
There is no good (we agree here). There only is "not obviously bad".
Just like a car whose engine check light is off isn't by definition a
good car.
> What are the exceptions to the two answer to above questions?
Warehousing.
> What are the exceptions to the exceptions?
Too many $ spent on memory.
You never can have clear rules. You only can have indicators. The ability to separate an indicator from a rule is part of teh job. I don't think we are on opposing ends here. I just find the word "useless" swinging the pendulum way too far to the other end.
Cheers
Serge
-- Serge Rielau DB2 Solutions Development IBM Toronto LabReceived on Mon Mar 17 2008 - 06:30:49 CDT