As a DBA that has been investigating time and effort in the standby technology since Oracle Database version 8i, it has been interesting to see the improvements along the way. Physical standbys have proven standard from the very first version, but the older implementation required the DBA to create their own script to manually transfer the archived redo logs from the primary database to the standby. Since 10gR2, all standby technology has improved dramatically from the early versions. Redo Apply is now fully automated, resilient, and SSL-encrypted. SQL Apply has matured enough that a logical standby can be depended on if a DBA takes the time to follow the Oracle-recommended tuning steps.
In 10gR2, most of the scenarios that were previously highly detailed manual steps have been shortened to a single command using the Data Guard command-line utility in 11g. Oracle has extended the functionality of using Data Guard for other reasons than just disaster recovery with several optional...
