STARTING AN ORACLE DATABASE

You must perform some preliminary steps before attempting to start an instance of your database using SQL*Plus.

1. Ensure that environment variables are set so that you connect to the desired Oracle instance.
2. Start SQL*Plus without connecting to the database:
   

   SQLPLUS /NOLOG
   
   

3. Connect to Oracle Database as SYSDBA:
   

   CONNECT username/password AS SYSDBA