Scenario: findById on an order with 1 item, then on an order with 5 items — no
@EntityGraph, no fetch annotation, this is the default and only behaviour.

statements for 1-item order:  2   (items loaded: 1)
statements for 5-item order:  2   (items loaded: 5)

Both counts are the same. There is no lazy vs eager choice to make because
Spring Data JDBC has no lazy loading: findById always returns the complete
aggregate. Compare to JpaBehaviorTest scenario 02, where the naive path is O(N)
in the number of orders touched, not items.