Hit Ratios have their uses
This attached document is in RTF format, size 20K
The content started life as a presentation at the UK Oracle User Group conference in 2001, and the backing article was first published on the website of Miracle A/S in Denmark. The article isn’t entirely serious – but contains a couple of points that are worth thinking about as you struggle to “tune” a system. It was only very recently that I realized that I hadn’t published the text on my own web site.
Update 3rd Jan 2005:
I received an email recently asking me about problems with hit ratios (the sender had seen a reference to some work of mine that Cary Millsap had referenced in his book Optimizing Oracle Performance). The reference was to a presentation called “The Database gets better, but the Metrics look worse” which I had given at IOUG Live! in 2003. This presentation was actually an updated version of the “FAN Hit Ratio” presentation – but there is some material in it that wasn’t in the original paper, so I have uploaded the “whitepaper” and a pdf of the slides.