Buffer cache LRU
Date: Sun, 3 Jan 2010 01:52:50 -0600
Few Doubts regarding oracle buffer cache. Here is the documentation link from 11g R2.
<http://download.oracle.com/docs/cd/E11882_01/server.112/e10713/memory.htm#i12483> "The database uses a sophisticated algorithm to make buffer access efficient. Pointers to dirty and nondirty buffers exist on the same least recently used (LRU) list, which has a hot end and cold end. A cold buffer is one that has not been recently used. A hot buffer is frequently accessed and has been recently used."
Now, i was under impression that there is a different LRU which is LRUW for write list but this says LRU maintains both cold, dirty, free, hot all pointers.
Can someone please explain this and also i had few question
- How to you find that particular buffer in hot, cold or dirty ?
- How to find buffer is in which list LRU or LRUW ?
To find this do we need SGA dump and if yes where to find this information.
-- Thanks & Regards, Taral Desai Samuel Goldwyn<http://www.brainyquote.com/quotes/authors/s/samuel_goldwyn.html> - "I'm willing to admit that I may not always be right, but I am never wrong." -- http://www.freelists.org/webpage/oracle-lReceived on Sun Jan 03 2010 - 01:52:50 CST