Question

The purpose is to send extra information to triggers like current user id from a web application. Since a connection pool is used, and same user id is used for all connections how do I pass the original web user id to trigger? It is a java based application.

Answer 1

If you can’t touch the application code and the application itself does not pass this information to the database already, you’re at an impasse. The only way to make that information available to back-end code is for the middle tier to pass it in.

Oracle provides a number of ways for applications to pass information from the middle-tier to the back end but the application has to be built to take advantage of them. The DBMS_APPLICATION_INFO package, for example, has a set_client_info procedure that allows the middle tier to pass in the name of the middle tier user that your back end trigger could query. You can also use Oracle contexts if you want a more general mechanism. Either of these approaches, however, realistically require that the Java application be written to pass this information to the back-end when connections are retrieved from the connection pool.