How does Oracle find a block in the buffer cache.

I have been reading a book on Operating System architecture and the section on caching has really peaked my curiosity. Of course while reading this material I tried to relate it to how Oracle works and what I came up with is I really don't know. In the book they define 3 types of mappings from the lower level (memory) to upper level (L1 cache) which are direct, set-associative and fully associative. I was wondering what Oracle uses as an algorithm to find buffers in the cache. The only option I could see as valid is fully associative (any block could end up in any buffer) however doesn't that imply that oracle has to scan all blocks to find the correct buffer in the cache?  If this is the case won't performance suffer as we have larger buffer caches?

I would appreciate some insight on the subject.

Thanks,
Scott Watson. Received on Thu Nov 15 2001 - 09:39:22 CST