Advantage of RAC

Oracle Real Application clusters allows multiple instances to access a single database. Instance running on multiple server nodes access the common set of datafiles compromising a single database.

Advantages:

1. High availability—Provide continuous uptime for database applications
2. On-demand scalability—Expand capacity by simply adding servers to your cluster
3. Lower computing costs—Use low-cost commodity hardware and reduce cost of downtime
4. High performance—Runs faster than the fastest mainframe
5. Grid computing—Oracle RAC is the foundation for grid computing