storm-core/src/jvm/org/apache/storm/trident/JoinOutFieldsMode.java

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.storm.trident;

/**
 * This enum defines how the output fields of JOIN is constructed.
 *
 * If user specifies COMPACT while calling JOIN, the tuples emitted from the join will contain:
 * First, the list of join fields. Please note that joining fields are exposed only once from emitted tuples.
 * Next, a list of all non-join fields from all streams, in order of how the streams were passed to the join method.
 *
 * If user specifies PRESERVE while calling JOIN, the tuples emitted from the join will contain:
 * a list of all fields from all streams, in order of how the streams were passed to the join method.
 */
public enum JoinOutFieldsMode {
    COMPACT,
    PRESERVE
}