org.apache.hadoop.hive.ql.optimizer.SizeBasedBigTableSelectorForAutoSMJ Maven / Gradle / Ivy
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/**
* 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.List;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hive.conf.HiveConf;
import org.apache.hadoop.hive.ql.exec.CommonJoinOperator;
import org.apache.hadoop.hive.ql.exec.Operator;
import org.apache.hadoop.hive.ql.exec.TableScanOperator;
import org.apache.hadoop.hive.ql.metadata.Partition;
import org.apache.hadoop.hive.ql.metadata.Table;
import org.apache.hadoop.hive.ql.plan.OperatorDesc;
/*
* This is a pluggable policy to chose the candidate map-join table for converting a join to a
* sort merge join. The largest table is chosen based on the size of the tables.
*/
public abstract class SizeBasedBigTableSelectorForAutoSMJ {
protected void getListTopOps(
Operator op, List topOps) {
if ((op.getParentOperators() == null) ||
(op.getParentOperators().isEmpty())) {
return;
}
for (Operator parentOp : op.getParentOperators()) {
if (parentOp instanceof TableScanOperator) {
topOps.add((TableScanOperator) parentOp);
} else if (parentOp instanceof CommonJoinOperator) {
topOps.add(null);
} else {
getListTopOps(parentOp, topOps);
}
}
}
private long getSize(HiveConf conf, String size, Path path) {
// If the size is present in the metastore, use it
if (size != null) {
try {
return Long.valueOf(size);
} catch (NumberFormatException e) {
return -1;
}
}
try {
FileSystem fs = path.getFileSystem(conf);
return fs.getContentSummary(path).getLength();
} catch (Exception e) {
return -1;
}
}
protected long getSize(HiveConf conf, Table table) {
Path path = table.getPath();
String size = table.getProperty("totalSize");
return getSize(conf, size, path);
}
protected long getSize(HiveConf conf, Partition partition) {
Path path = partition.getDataLocation();
String size = partition.getParameters().get("totalSize");
return getSize(conf, size, path);
}
}