| /* |
| * Copyright (c) 2011, 2020 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 v. 2.0 which is available at |
| * http://www.eclipse.org/legal/epl-2.0, |
| * or the Eclipse Distribution License v. 1.0 which is available at |
| * http://www.eclipse.org/org/documents/edl-v10.php. |
| * |
| * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause |
| */ |
| |
| // 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; |
| } |