Chapter 10. Oracle and High Availability
The
data stored in the databases of your organization's
computer systems is extremely valuable. In many cases, this data
represents your organization's most valuable asset.
Protecting this asset is crucial for any Oracle site. As a DBA, system administrator, or system architect,
you'll probably have to use a variety of options and
techniques to ensure that your data is adequately protected from a
catastrophe. Of course, implementing proper backup operations is the
foundation of any disaster-prevention strategy, but there are other
ways to avoid a variety of disasters, from simple disk failures to a
complete failure of your primary site. Computer hardware is, by and large, extremely reliable, which may
make it tempting for you to postpone thinking about disaster
recovery. Most software is also very reliable, and the Oracle
database protects the integrity of its data even in the event of a
software failure. However, components and software will, at times,
fail, and the more components are involved, the greater the
likelihood of a disaster. The
difference between an inconvenience and a disaster is the presence or
absence of adequate recovery plans, so it's best to
understand all of the options available with Oracle so you can choose
the best approach for your particular site. With Oracle, you can guarantee that your precious data is highly
available. Some of the types of high-availability features are part
of the Oracle software, such as Oracle's automatic
crash recovery and the Real Application Clusters option. Other
features are available from third-party vendors, such as hardware
failover solutions and some backup managers. Finally, some of the
most important features of a high-availability solution are dependent
on implementing appropriate procedures to safeguard your data. This
chapter covers all three aspects of high availability. |