Databases Reference
In-Depth Information
Oracle Data Guard
You can use Oracle Data Guard functionality to provide data redundancy. Changes
made by transactions are replicated synchronously or asynchronously to other da‐
tabases. If the primary database fails, the data is available from the other databases.
Oracle Data Guard is described in more detail in
Chapter 11
.
Real Application Clusters
Real Application Clusters can increase the scalability of the Oracle Database over
multiple nodes in a cluster. But by supporting multiple instances with full access to
the same database, RAC also provides the highest levels of availability for protection
from the failure of a node in a clustered environment. If one node fails, the surviving
nodes provide continued access to the database. Grid computing deployment fur‐
ther extends availability capabilities.
Oracle Database 11
g
provides a number of high-availability enhancements, including
the ability to easily capture diagnostic information about database failures. For a more
detailed discussion of high-availability features and options, see
Chapter 11
.
