In this tutorial, you’ll learn everything about the error “ORA-03150: end-of-file on communication channel for database link” in Oracle, why this error appears and how you can resolve it in simple steps.
Oracle Error Message
This is how the Oracle error message ORA-03150 looks like in general.
ORA-03150: end-of-file on communication channel for database link
Reason for the Error
The connection between the client and the remote server process was broken.
ORA-03150 indicates that the communication channel between the local database and a remote database via a database link has been unexpectedly terminated. This error typically occurs when the network connection between the databases fails or when the remote database is unexpectedly shut down.
The following are some scenarios that could result in this error:
- Issues with database network connectivity
- A firewall prevents communication between databases.
- The remote database was unexpectedly shut down or restarted.
- A database link that has expired as a result of inactivity.
Solution
- Look in the alert.log file of the remote server for any errors. Also, check to see whether the remote server process is dead and whether a trace file was generated at failure time.
- Verify network connectivity: Ensure that the network connectivity between the databases is operational. Check that the network firewall is not interfering with database communication.
- Restart the remote database: If the remote database was unexpectedly shut down or restarted, restart it to re-establish the connection.
- Increase the timeout limit: If the database link has timed out due to inactivity, use the SQL statement ALTER SESSION SET DISTRIBUTED LOCK TIMEOUT to increase the timeout limit.
- Drop and re-create the database link: If none of the above solutions work, try dropping and re-creating the database link. Before recreating the link, double-check the connection details and permissions.
Here is an example of how to fix ORA-03150 by increasing the timeout limit:
ALTER SESSION SET DISTRIBUTED_LOCK_TIMEOUT=600;
This raises the timeout limit to 600 seconds, which should give the database link enough time to establish and maintain a connection. However, it is critical to understand that increasing the timeout limit may cause the database to hang or become unresponsive if there is a network connectivity issue.
