public @interface BatchFetch
A BatchFetch annotation can be used on any relationship mapping,
(OneToOne, ManyToOne, OneToMany, ManyToMany, ElementCollection, BasicCollection, BasicMap).
It allows the related objects to be batch read in a single query.
Batch fetching can also be set at the query level, and it is
normally recommended to do so as all queries may not require batching.
Define the default batch fetch size.
This is only used for IN type batch reading and defines
the number of keys used in each IN clause.
The default size is 256, or the query's pageSize for cursor queries.