Oracle® Database Upgrade Guide
Real Application Clusters (RAC) comprises several Oracle instances running on
multiple clustered computers, which communicate with each other by means of a
so-called interconnect. RAC uses cluster software to access a shared database that
resides on shared disk. RAC combines the processing power of these multiple
interconnected computers to provide system redundancy, near linear scalability, and
high availability. RAC also offers significant advantages for both OLTP and data
warehouse systems and all systems and applications can efficiently exploit clustered
environments. ...
