Re: testing memory parameters

From: Serge Rielau <>
Date: Mon, 17 Mar 2008 07:30:49 -0400
Message-ID: <>

> 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?

> 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.


Serge Rielau
DB2 Solutions Development
IBM Toronto Lab
Received on Mon Mar 17 2008 - 06:30:49 CDT

Original text of this message