6.2. Better Performance

A nice side effect of keeping the persistence context valid beyond a single stateless method call is improved database performance. We already know that lazy loading results in better database performance, but we are talking about another performance improvement in a somewhat opposite direction: the reduction of database roundtrips.

A major performance problem with database-driven web applications is that many of those applications are chatty. A chatty web application saves information to the database whenever the user changes anything, as opposed to queueing database operations and executing them in a batch. Since a roundtrip to the database, potentially over the network, is much slower than a method call inside the application server, it slows down the application significantly.