Module org.eclipse.persistence.core
Package org.eclipse.persistence.annotations

Annotation Type BatchFetch

@Target({METHOD,FIELD}) @Retention(RUNTIME) 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.
Since:
EclipseLink 2.1

  • Optional Element Summary

    Optional Elements
    Modifier and Type
    Optional Element
    Description
    int
    size
    Define the default batch fetch size.
    BatchFetchType
    value
    (Optional) The type of batch-fetch to use.

  • Element Details

    • value

      BatchFetchType value
      (Optional) The type of batch-fetch to use. Either JOIN, EXISTS or IN. JOIN is the default.
      Default:
      JOIN

    • size

      int size
      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.
      Default:
      -1