org.apache.hadoop.hive.ql.optimizer.LeftmostBigTableSelectorForAutoSMJ Maven / Gradle / Ivy
/**
* 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.hadoop.hive.ql.optimizer;
import java.util.Set;
import org.apache.hadoop.hive.ql.exec.JoinOperator;
import org.apache.hadoop.hive.ql.parse.ParseContext;
/*
* This is a pluggable policy to chose the candidate map-join table for converting a join to a
* sort merge join. The leftmost table is chosen as the join table.
*/
public class LeftmostBigTableSelectorForAutoSMJ implements BigTableSelectorForAutoSMJ {
public int getBigTablePosition(ParseContext parseContext, JoinOperator joinOp,
Set bigTableCandidates) {
return 0;
}
}