The core enabler for Oracle's Data Management capabilities revolves around Oracle Real Application Cluster (RAC) technology. There have been many discussions about RAC, so we don't have a lot of new things to say here, but it is certainly worth a mention at a high level. The following figure shows a typical RAC implementation. We can use this model to describe what RAC technology is.
Oracle RAC databases differ architecturally from single-instance Oracle databases in that each Oracle RAC database instance also has:
At least one additional thread of redo for each instance
An instance-specific undo table-space
The combined processing power of the multiple servers can provide greater throughput and Oracle RAC scalability than is available from a single server.
Traditionally, an Oracle RAC environment is located in one data center, but you can configure Oracle RAC on an extended distance cluster. This is an architecture which provides fast recovery from a site failure and allows for...