As we all know Active Dataguard is a licensed feature and whilst there is no parameter to control, indeed if just in case if you do not have a license and by chance your DBA has opened the standby database in readonly and started MRP then you are in troubles as it activates the Active Dataguard.
In earlier versions when you open the standby in readonly and try to start MRP it will not start. But from 11g Onwards , MRP will still start and that activates your active dataguard feature.
If you want to disable completely that feature by not accidentally enabling it, there is undocumented parameter called
SQL> alter system set “_query_on_physical”=false scope=spfile;
System altered.
And when you open readonly and try to start MRP
ORA-16669: instance cannot be opened because the Active Data Guard option is disabled
-Thanks
Thanks for sharing Good Information.