org.apache.kylin.engine.mr.steps.FactDistinctColumnPartitioner Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
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* 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
*
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package org.apache.kylin.engine.mr.steps;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Partitioner;
import org.apache.kylin.common.util.BytesUtil;
/**
*/
public class FactDistinctColumnPartitioner extends Partitioner {
private Configuration conf;
@Override
public int getPartition(Text key, Text value, int numReduceTasks) {
if (key.getBytes()[0] == FactDistinctHiveColumnsMapper.MARK_FOR_HLL) {
// the last reducer is for merging hll
return numReduceTasks - 1;
} else {
int colIndex = BytesUtil.readUnsigned(key.getBytes(), 0, 1);
return colIndex;
}
}
}