In this example, a J2C alias named mySQL is created.
On the WebSphere server, the J2C aliases you've created will be in the security.xml file.
IBM WebSphere - JDBC data source and J2C alias
Configure a Java app to use a JDBC
Connect to a SQL database via DataSource
Connect to a SQL database via DriverManager
At Monitoring and Tuning > Performance Viewer > Current activity > your application server > Summary Reports > JDBC Connection Pools > your JDBC provider > your JNDI, the connection count should be 1 for the single connection to the database.