Role of the Listener in Oracle Database and Configuration

The Listener in Oracle database acts as a mediator between the client applications and the database instance. It listens for incoming client connections and establishes a connection to the appropriate database service. The listener is essential for clients to communicate with the Oracle database.

To configure the listener in Oracle database, you can follow these steps:

1. Locate the listener.ora file, usually found in the $ORACLE_HOME/network/admin directory.
2. Edit the listener.ora file using a text editor.
3. Define the protocol addresses for the listener, such as TCP/IP or IPC.
4. Specify the services that the listener should listen for and the associated database instance names.
5. Save the changes to the listener.ora file.
6. Restart the listener process using the lsnrctl utility.

By correctly configuring the listener in Oracle database, you ensure that client applications can connect to the database instance and access the necessary data.