Oracle Data Guard 11g Handbook

CHAPTER 9Active Data Guard

In Chapter 2 we discussed the configuration and implementation of physical standby databases. The physical standby database itself is not new to Oracle. In fact, Oracle Database 7.3 was the first version that officially supported standby databases. In Oracle Database 7.3, however, all redo log application had to be performed manually. In Oracle Database 8i, the concept of shipping and apply of redo logs was introduced. At the same time, the standby database could be opened in a read-only mode once the application of the logs was stopped. In Oracle Database 9i, both the Data Guard Broker and the concept of protection modes to prevent data variances between the primary and standby were introduced. In Oracle Database 9 ...