There are a number of restrictions that you should be aware
of if you are planning to deploy the HADR feature in multiple standby
mode.
The restrictions are as follows:
- You can have a maximum of three standby databases: one principal
standby and up to two auxiliary standbys.
- Only the principal standby supports all the HADR synchronization
modes; all auxiliary standbys will be in SUPERASYNC mode.
- IBM® Tivoli® System Automation for Multiplatforms (SA MP)
support applies only between the primary HADR database and its principal
standby.
- The hadr_target_list database configuration
parameter must be set on all the databases in the multiple standby
setup. Each standby must include the primary in its hadr_target_list setting.