Uninstall Oracle 19c in Windows and Unix/Linux to remove Oracle software and configuration files completely.

Sometimes we need to remove or un-install Oracle Database from our computer. These topics describe how to remove Oracle software and configuration files for version Oracle 19c in Windows and Unix/Linux.

Uninstalling oracle database is little bit complex in 12c because it sets different file in different location during install. If properly those file is not deleted Oracle will not install next time. But in 19c, it is easy to remove Oracle software and configuration files on the operating system for a specific Oracle home using deinstall command.

Before Execute Command

• Before deinstalling oracle software, make sure you have stopped the oracle databases (and other services) running from the ORACLE_HOME. For database shutdown, after going sqlplus, execute the following command:

shutdown

• Stop listener

lsnrctl stop

Syntax

The deinstall command uses the following syntax:

(./deinstall [-silent] [-checkonly] [-paramfile complete path of input response file] 
[-params name1=value name2=value . . .] 
[-o complete path of directory for saving files] 
[-tmpdir complete path of temporary directory to use] 
[-logdir complete path of log directory to use] [-local] [-skipLocalHomeDeletion] 
[-skipRemoteHomeDeletion] [-help]

Use -silent flag to run deinstall in noninteractive mode. This option requires one of the following:

• A working system that it can access to determine the installation and configuration information. The -silent flag does not work with failed installations.
• A response file that contains the configuration values for the Oracle home that is being deinstalled or deconfigured.

For understanding all option, https://docs.oracle.com/en/database/oracle/oracle-database/19/ladbi/oracle-deinstallation-tool-deinstall.html#GUID-71E860C5-4E1E-4D2F-AFD1-141709A172C0

Execute Command

At now, run the deinstall command from an Oracle home directory after installation.

$ORACLE_HOME/deinstall/deinstall

Output

…..
Successfully deleted directory '/u01/app/oraInventory' on the local node.
Oracle Universal Installer cleanup was successful.


Run 'rm -rf /etc/oraInst.loc' as root on node(s) 'medmgmt-193' at the end of the session.

Run 'rm -rf /opt/ORCLfmap' as root on node(s) 'medmgmt-193' at the end of the session.
Run 'rm -rf /etc/oratab' as root on node(s) 'medmgmt-193' at the end of the session.
Review the permissions and contents of '/u01/app/oracle' on nodes(s) 'medmgmt-193'.
If there are no Oracle home(s) associated with '/u01/app/oracle', manually delete '/u01/app/oracle' and its contents.

After Execute Command

Sometimes ORACLE software installation gets corrupted and in such case, above deinstallation utilities will not help you to remove oracle software. Use below method to remove the oracle home using Linux commands.

According output status, execute remove  command:

sudo rm -rf /etc/oraInst.loc
sudo rm -rf /opt/ORCLfmap
sudo rm -rf /etc/oratab 

Finally Delete ORACLE_HOME

cd $ORACLE_HOME
rm -Rf *

Delete ORACLE_BASE

cd $ORACLE_BASE
rm -Rf *

I think, it will help you. Enjoy!