A multi-user application working against a database cannot be efficient if it doesn't use connection pooling. Middleware can offer this service, but not all applications rely on such middleware. These applications must then come up with their own way to pool connections. The Apache Tomcat project doesn't only come with the most popular web container but also with a performant connection pool library, Tomcat JDBC. This post covers how to configure Tomcat JDBC in a typical Maven + Spring application.