Opening the standby database in read-only mode

One of the biggest achievements of using HADR is that the standby database can be opened in read-only mode and used for reporting purposes. For example, in some hardware replication solutions, it is not possible to open the standby/replicated database. In this way, you can release the primary database from additional processing effort induced by possible intensive reports. Issuing read-only queries on the standby database does not interfere with the log replay mechanism, so it has no impact on data synchronization.

Getting ready…

For this recipe, we will run some simple queries on the standby database to demonstrate how to use the standby database in read-only mode.

How to do it…

1. To enable read-only mode for the standby database, we need to modify the DB2_HADR_ROS registry variable to ON.

   	[db2inst1@nodedb22 ~]$ db2set DB2_HADR_ROS=ON
   

2. Restart the instance.

   Note

   Try to use a different IP address for connecting to the standby database in read-only mode...