/******************************************************************************* | |
* Copyright (c) 2011, 2013 Oracle and/or its affiliates. All rights reserved. | |
* This program and the accompanying materials are made available under the | |
* terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0 | |
* which accompanies this distribution. | |
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html | |
* and the Eclipse Distribution License is available at | |
* http://www.eclipse.org/org/documents/edl-v10.php. | |
* | |
* Contributors: | |
* James Sutherland - initial implementation | |
******************************************************************************/ | |
package org.eclipse.persistence.annotations; | |
import java.lang.annotation.Retention; | |
import java.lang.annotation.Target; | |
import static java.lang.annotation.ElementType.METHOD; | |
import static java.lang.annotation.ElementType.FIELD; | |
import static java.lang.annotation.RetentionPolicy.RUNTIME; | |
/** | |
* 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. | |
* | |
* @author James Sutherland | |
* @since EclipseLink 2.1 | |
*/ | |
@Target({METHOD, FIELD}) | |
@Retention(RUNTIME) | |
public @interface BatchFetch { | |
/** | |
* (Optional) The type of batch-fetch to use. | |
* Either JOIN, EXISTS or IN. | |
* JOIN is the default. | |
*/ | |
BatchFetchType value() default BatchFetchType.JOIN; | |
/** | |
* 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. | |
*/ | |
int size() default -1; | |
} |