This was a new concept introduced in 11g version of oracle. When AWR report indicates that when we need much larger database buffer cache and when we also notice that shared pool is properly sized, we can enable database smart flash cache by setting the parameters :
1.db_flash_cache_file
2.db_flash_cache_size
sys>show parameter db_flash_cache;
sys>alter system flush db_cache; -- if we do this it degrades the performance.
Once we enable database smart flash cache, oracle evicts some buffers to smart flash cache. These buffers are moved backed to database buffer cache whenever there is a demand.
This option is available only for Linux & Sun Solaris.
Oracle has introduced the following hardware devices to enable flash cache
1.Sun storage FI100 flash array
1.Sun flash axilarator F20 PCIE card
