Just a quick note that there is now a patch for the 11.2 Oracle Enterprise Linux (OEL) database ports to enable the database flash cache (not to be confused with the Exadata flash cache). Go to the My Oracle Support site [link] and search for patch 8974084 - META BUG FOR FLASH CACHE 11.2PL BUGS TO BACKPORT TO 11.2.0.1 OEL

You can download Oracle Database 11g Release 2 from OTN.

Note: The db flash cache is already built into the Solaris ports so no patch is needed.