Executing a getter — representing a one-to-many or many-to-many association — on an entity causes one or n (with n entries in the collection) database calls, depending on the fetching strategy (see fetch strategies). This is a nasty little detail that may cause performance bottlenecks. Changing the fetch type (lazy/eager) may not be appropriate, since an association is generally used in more than one context, so there may be contradictory concerns. Generally spoken, an eager fetching is only in rare occasions a good idea on one-to-many or many-to-many associations, since this leads to the cartesian product problem (simply put, you have to read [nearly] the hole db in order to get one entity). Fortunately there is another solution that enables overriding a lazy fetch type in a dedicated JPQL-Query. This may entail a hole bunch of JPQL queries you will have to write (not more queries to execute on the db!!!), since you want to eagerly fetch an association in one situation but not in another.
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