Time for action – changing the protection mode with SQL*Plus

Now we'll convert Data Guard's configuration from Maximum Performance to Maximum Protection and then to the Maximum Availability mode using SQL*Plus commands. At the end, we'll convert it back to the Maximum Performance mode.

1. We have a physical standby configuration, which is in the Maximum Performance mode (by default) with ASYNC redo transport, without standby redo logs, and does not use Real-Time Apply. We'll try to convert it to the Maximum Protection mode. Let's execute the conversion command in the primary database without any change in the configuration as follows:

   SQL> SELECT PROTECTION_MODE FROM V$DATABASE;
   
   PROTECTION_MODE
   --------------------
   MAXIMUM PERFORMANCE
   
   SQL> ALTER DATABASE SET STANDBY DATABASE TO MAXIMIZE PROTECTION;
   ALTER DATABASE SET STANDBY DATABASE TO MAXIMIZE PROTECTION
   *
   ERROR at line 1:
   ORA-01126: database must be mounted in this instance and not open in any instance

2. It's not possible to convert a...