Ensure that the database configuration file is correctly configured and that the database service is properly installed on the server.
Log in to the server operating system with administrator privileges.
Open the command line window and use the command “sqlplus / as sysdba” to log in to the database.
Start the database instance by entering the startup command.
Verify that the database has been successfully started, you can check the status of the database by executing the command select status from v$instance;.
If the database fails to start, one can check the database log file for troubleshooting and attempt to restart the database.
