How to drop DBConsole using EMCA or manually (with and without repository)

How to drop DBConsole configuration along with the repository using EMCA? 

To completely remove the DBConsole configuration files and repository run below command. 

<ORACLE_HOME>/bin/emca -deconfig dbcontrol db -repos drop

Enter the following information:
Database SID: orcl
Listener port number: 1521
Password for SYSMAN user:
Do you wish to continue? [yes(Y)/no(N)]: Y

This command will remove the DBConsole configuration files under <ORACLE_HOME>/<Hostname_SID>,
<ORACLE_HOME>/oc4j/j2ee/OC4J_DBConsole_<Hostname>_<SID>
as well as DBConsole repository from the Database.

How to drop DBConsole configuration files using EMCA (leave repository intact) ?

 To remove DBConsole configuration files (leaving repository intact) run following EMCA command.

<ORACLE_HOME>/bin/emca -deconfig dbcontrol db

Enter the following information:
Database SID: orcl
Do you wish to continue? [yes(Y)/no(N)]:

This command will remove only the DBConsole configuration files which are under <ORACLE_HOME>/<Hostname_SID> and <ORACLE_HOME>/oc4j/j2ee/OC4J_DBConsole_<Hostname>_<SID>

How to drop DBConsole repository objects manually ?

DBConsole repository can be dropped manually by executing following SQL statements.

Step 1: Drop AQ related objects in the SYSMAN schema
Logon SQLPLUS as user SYS
SQL> exec DBMS_AQADM.DROP_QUEUE_TABLE(queue_table=>'SYSMAN.MGMT_NOTIFY_QTABLE',force=>TRUE);

Step 2: Drop the DB Control Repository Objects
Logon SQLPLUS as user SYS or SYSTEM, and drop the sysman account and management objects:
SQL> SHUTDOWN IMMEDIATE;
SQL> STARTUP RESTRICT;
SQL> EXEC sysman.emd_maintenance.remove_em_dbms_jobs;
SQL> EXEC sysman.setEMUserContext('',5);
SQL> REVOKE dba FROM sysman;
SQL> DECLARE
CURSOR c1 IS
SELECT owner, synonym_name name
FROM dba_synonyms
WHERE table_owner = 'SYSMAN';
BEGIN
FOR r1 IN c1 LOOP
IF r1.owner = 'PUBLIC' THEN
EXECUTE IMMEDIATE 'DROP PUBLIC SYNONYM '||r1.name;
ELSE
EXECUTE IMMEDIATE 'DROP SYNONYM '||r1.owner||'.'||r1.name;
END IF;
END LOOP;
END;
/
SQL> DROP USER mgmt_view CASCADE;
SQL> DROP ROLE mgmt_user;
SQL> DROP USER sysman CASCADE;
SQL> ALTER SYSTEM DISABLE RESTRICTED SESSION;

How to delete DBConsole configuration files manually?

To manually delete DBConsole configuration files, remove the following directories from the filesystem:

<ORACLE_HOME>/<hostname_sid>
<ORACLE_HOME>/oc4j/j2ee/OC4J_DBConsole_<hostname>_<sid>

If the dbcontrol is upgraded from lower version, for example, from 10.2.0.3 to 10.2.0.4, then the following directory also needs to be removed from the file system.
<ORACLE_HOME>/<hostname_sid>.upgrade
<ORACLE_HOME>/oc4j/j2ee/OC4J_DBConsole_<hostname>_<sid>.upgrade

NOTE : Be careful while removing these directories as one should NOT remove OC4J_DBConsole or any other directory by mistake, they are very important. You need to delete only those directories with <hostname>_<sid> where hostname is the hostname of the server and SID should be the database SID.

On Windows you also need to delete the DB Console service:
Using regedit
- run regedit
- navigate to HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Services
- locate the OracleDBConsole<sid> entry and delete it
Or
On Windows XP and Windows Server 2003 you can run the following from the command line:
CMD> sc delete <service_name>
- where <service_name> is the DB Control service name (typically: OracleDBConsole<sid>)
Or
CMD> nmesrvops delete <servicename>
- where <service_name> is the DB Control service name (typically: OracleDBConsole<sid>)