* When you create a data source using the Administration Console, the Administration Console automatically sets the Test Table Name attribute for a data source based on the DBMS that you select. The Test Table Name attribute is used in connection testing which is optionally performed periodically or when you create or reserve a connection, depending on how you configure the testing options. For database tests to succeed, the database user used to create database connections in the data source must have access to the database table. If not, you should either grant access to the user (make this change in the DBMS) or change the Test Table Name attribute to the name of a table to which the user does have access (make this change in the WebLogic Server Administration Console).
* To manually test a connection from a data source, you can use the Test Data Source feature on the JDBC Data Source: Monitoring: Testing page in the Administration Console (see " Test JDBC data sources") or the testPool() method in the JDBCDataSourceRuntimMBean. To test a database connection from a data source, Test Reserved Connections must be enabled and Test Table Name must be defined in the data source configuration. Both are defined by default if you create the data source using the Administration Console.
When you test a data source, WebLogic Server reserves a connection, tests it using the query defined in Test Table Name, and then releases the connection.
Reference: Configuring and Managing JDBC Data Sources for Oracle WebLogic Server, Tuning Data Source Connection Pools