REAL TIME QUERY is only active with Active Data Guard. Since you are opening the Database and make the RTA active.
If you do not want to use REAL TIME QUERY, you should keep your database in MOUNT state.
Do you need to start your database with STARTUP command? Why don't use only STARTUP MOUNT? Is this Standby configured in SINGLE or RAC?
it is for standalone database (not RAC)
yes, users can start the database with mount option, but they have to keep in mind that they do not have to issue a "STARTUP",
so it is a production rule that oracle doesn't handle.
Second, it will give a little more complexity in startup scripts (first mount, identify the role, and then open if it is a primary.
In 10gr2 just startup in all cases ....
that's why i'd like to know if there is a possibility to permanently disable REAL TIME APPLY ...
ultimately if the users aka dba has the ability to start the database. Restrict them to a sudo command by set something in place to only allow the database to start up in read only or edit the configuration on the standby dgmgrl that way if it is started the the redo apply is off.
worst case educate those that keep starting it :)
DGMGRL> edit database <name> set state=apply-off;
sql> alter database open read only;