Oracle Database Discussions

Hi Friends,

from docs i read the following

A cold buffer is a buffer that has not been recently used according to LRU algorithm

Also from the following link

http://www.adp-gmbh.ch/ora/concepts/cache.html

Cold and hot area
+Each pool's LRU is divided into a hot area and a cold area. Accordingly, buffers with in the hot area are hot buffers (and buffers in the cold are are called cold buffers). By default, 50% of the buffers belong to the cold area and the other 50% belong to the hot area. This behaviour can be changed with dbpercent_hot_default (for the default pool) dbpercent_hot_recycle (for the recycle pool) and dbpercent_hot_keep (for the keep pool). A newly read db block will be inserted between the cold and the hot area such that it belongs to the hot area. This is called midpoint insertion. However, this is only true for single block reads, multi block reads will be placed at the LRU end.+

i just want to know is cold buffer is also a dirty buffer? because DBWR will write only dirty buffers to datafiles.right?

please explain in detail

thanks in advance.