关于Oracle 11gR2中的Database Smart Flash Cache特性以及该特性所适用的操作系统

参考自：

How To Size the Database Smart Flash Cache (文档 ID 1317950.1)

首先是对Database Smart Flash Cache的介绍：

The Database Smart Flash Cache is a new feature in Oracle Database 11g Release 2 (11.2).
The Database Smart Flash Cache is a transparent extension of the database buffer cache using solid state device (SSD) technology.
The SSD acts as a Level 2 cache to the (Level 1) SGA.

Database Smart Flash Cache can greatly improve the performance of Oracle databases by reducing the amount of disk I/O at a much lower cost than adding an equivalent amount of RAM.

Database Smart Flash Cache特性所适用的操作系统：

Your database is running on the Solaris or Oracle Linux operating systems.
The flash cache is supported on these operating systems only.

那么好了,在RHEL设置了Flash Cache后，数据库实例是起不来的，如下：

SQL> startup;
ORA-00439: feature not enabled: Server Flash Cache

而Oracle Linux下的数据库实例就能正常启动