ORA-01665: control file is not a standby control file

Problem Description
While recovering standby database, using command alter database recover managed standby database disconnect from session it fails with message ORA-01665: control file is not a standby control file like below.
SQL> alter database recover managed standby database disconnect from session;
alter database recover managed standby database disconnect from session
*
ERROR at line 1:
ORA-01665: control file is not a standby control file

Cause of the Problem
The error occurred because there was an attempt to mount, recover, or activate a standby database without a standby controlfile. In order to recover standby database you need standby controlfile. If you don't have standby controlfile and use normal controlfile then above error will occurred.

Solution of the Problem
The solution is to create a standby controlfile before attempting to use the database as a standby database.

1)So if you don't have a standby controlfile for your standby first create a standby controlfile from source database using command,

SQL>alter database create standby controlfile as 'standbyctlfile.ctl';

2)Transfer this standby controlfile into standby database.

3)Edit the standby database pfile control_files parameter in order to effect the changes.

4)Startup the database in nomount stage.
SQL> startup nomount pfile='your_pfile_location';

5)Create spfile from the pfile.
SQL> create spfile from pfile='your_pfile_location';

6)Shutdown the database.
SQL>shutdown immediate;

7)Start the database in mount state.
SQL>startup mount;

8)On the standby database, start redo apply by following command.
SQL>alter database recover managed standby database disconnect from session;

Note that only step 1) need to be performed in primary database only. All other steps will be done in standby database.

Related Documents
http://arjudba.blogspot.com/2009/04/different-types-of-standby-database-in.html
http://arjudba.blogspot.com/2009/04/what-is-oracle-data-guard.html