How to run two oracle instances in oracle 10g?

@lizzie 

To run two Oracle instances in Oracle 10g, follow these steps:

1. Verify that your system meets the requirements for running multiple instances. Ensure that you have enough memory and CPU resources to run two instances simultaneously.
2. Create a new listener for the second instance in Oracle Net Configuration Assistant. This will allow the second instance to listen on a different port than the first instance.
3. Modify the listener.ora file to include a new listener entry for the second instance. Make sure to specify a different port number for the second instance.
4. Create a new database for the second instance using the Database Configuration Assistant or manually using SQL scripts.
5. Modify the init.ora file for the second instance to specify a unique SID and other necessary parameters for the new database.
6. Start the second instance using the Oracle Enterprise Manager Console or command line tools like SQL*Plus.
7. Verify that both instances are running by checking the status of the listener and database using the lsnrctl and sqlplus commands.

By following these steps, you can successfully run two Oracle instances in Oracle 10g on the same server.