Dropping log file in standby database

Question

Please,
I need a help for the following issue:
I'm making a technical documentation on various event that occur on dataguard configuraation, right now I drop a redo log group file on primary database, and when I try to drop the equivalent log group file on standby database I got the following error:
SQL> alter database drop logfile group 3;
alter database drop logfile group 3
ERROR at line 1:
ORA-01156: recovery in progress may need access to files
this is the current state of the redolog file on standby database.
SQL> select group#,members,status from v$log;
GROUP# MEMBERS STATUS
1 3 CLEARING_CURRENT
3 3 CLEARING
2 3 CLEARING
Eventhough I do the following command on standby I also get an error.
SQL> ALTER DATABASE CLEAR LOGFILE GROUP 3;
ALTER DATABASE CLEAR LOGFILE GROUP 3
ERROR at line 1:
ORA-01156: recovery in progress may need access to files
Can someone tell me how to drop on dataguard configuration the redolog file on primary database and their corresponding on standby database
I'm working on 10 release 2, on Windows
Thanks you

Answer 1

Oracle Dataguard Concept and administration release 2,ref b14239: is my source but it doesn't work when trying to drop stanby group or logile member.
For example, if the primary database has 10 online redo log files and the standby
database has 2, and then you switch over to the standby database so that it functions
as the new primary database, the new primary database is forced to archive more
frequently than the original primary database.
Consequently, when you add or drop an online redo log file at the primary site, it is
important that you synchronize the changes in the standby database by following
these steps:
1. If Redo Apply is running, you must cancel Redo Apply before you can change the
log files.
2. If the STANDBY_FILE_MANAGEMENT initialization parameter is set to AUTO,
change the value to MANUAL.
3. Add or drop an online redo log file:
■ To add an online redo log file, use a SQL statement such as this:
SQL> ALTER DATABASE ADD LOGFILE '/disk1/oracle/oradata/payroll/prmy3.log'
SIZE 100M;
■ To drop an online redo log file, use a SQL statement such as this:
SQL> ALTER DATABASE DROP LOGFILE '/disk1/oracle/oradata/payroll/prmy3.log';
4. Repeat the statement you used in Step 3 on each standby database.
5. Restore the STANDBY_FILE_MANAGEMENT initialization parameter and the Redo Apply options to their original states.
Thank