org.apache.hadoop.hive.ql.optimizer.SparkMapJoinProcessor Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
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* 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
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package org.apache.hadoop.hive.ql.optimizer;
import java.util.List;
import org.apache.hadoop.hive.conf.HiveConf;
import org.apache.hadoop.hive.ql.ErrorMsg;
import org.apache.hadoop.hive.ql.exec.JoinOperator;
import org.apache.hadoop.hive.ql.exec.MapJoinOperator;
import org.apache.hadoop.hive.ql.exec.Operator;
import org.apache.hadoop.hive.ql.parse.SemanticException;
import org.apache.hadoop.hive.ql.plan.JoinCondDesc;
import org.apache.hadoop.hive.ql.plan.OperatorDesc;
import com.google.common.base.Preconditions;
public class SparkMapJoinProcessor extends MapJoinProcessor {
/**
* convert a regular join to a a map-side join.
*
* @param conf
* @param opParseCtxMap
* @param op join operator
* @param joinTree qb join tree
* @param bigTablePos position of the source to be read as part of
* map-reduce framework. All other sources are cached in memory
* @param noCheckOuterJoin
* @param validateMapJoinTree
*/
@Override
public MapJoinOperator convertMapJoin(HiveConf conf,
JoinOperator op, boolean leftSrc, String[] baseSrc, List mapAliases,
int bigTablePos, boolean noCheckOuterJoin, boolean validateMapJoinTree)
throws SemanticException {
// outer join cannot be performed on a table which is being cached
JoinCondDesc[] condns = op.getConf().getConds();
if (!noCheckOuterJoin) {
if (checkMapJoin(bigTablePos, condns) < 0) {
throw new SemanticException(ErrorMsg.NO_OUTER_MAPJOIN.getMsg());
}
}
// create the map-join operator
MapJoinOperator mapJoinOp = convertJoinOpMapJoinOp(conf,
op, op.getConf().isLeftInputJoin(), op.getConf().getBaseSrc(),
op.getConf().getMapAliases(), bigTablePos, noCheckOuterJoin);
// 1. remove RS as parent for the big table branch
// 2. remove old join op from child set of all the RSs
List> parentOps = mapJoinOp.getParentOperators();
for (int i = 0; i < parentOps.size(); i++) {
Operator parentOp = parentOps.get(i);
parentOp.getChildOperators().remove(op);
if (i == bigTablePos) {
List> grandParentOps = parentOp.getParentOperators();
Preconditions.checkArgument(grandParentOps.size() == 1,
"AssertionError: expect number of parents to be 1, but was " + grandParentOps.size());
Operator grandParentOp = grandParentOps.get(0);
grandParentOp.replaceChild(parentOp, mapJoinOp);
mapJoinOp.replaceParent(parentOp, grandParentOp);
}
}
return mapJoinOp;
}
}