8 My rule of thumb for IO subsystem read response time is 10 ms. While every application and IT organization has its own response time tolerances, I have never found an IO team comfortable with a 15 ms response time. A 10 ms or greater response time means not only are the blocks not cached, resulting in real physical IO activity, but there is also significant contention. I am in no way implying the IO subsystem is poorly configured, although it could be. I am simply stating Oracle's IO requirements have exceeded the IO subsystem's capacity.

9 Instrumentation involves injecting additional code into software to observe specific behavior. It is similar to the gauges and instruments on a car dashboard or my bright-red Honda VFR 800 Interceptor's speedometer-it provides internal functioning information. When the hooks needed to obtain this data are added as the application is built, instrumentation is easy. But most often, little thought is given to instrumentation. Oracle started instrumenting its kernel code with Oracle version 7.

11 The word practice used in conjunction with a medical doctor has always been a little unsettling. Even more personal was when my title at Oracle Corporation was, you guessed it, Practice Manager. As the joke went, Craig's not a real manager-he's just practicing to be one!