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package com.salesforce.phoenix.expression.function;
import java.util.List;
import org.apache.hadoop.conf.Configuration;
import com.salesforce.phoenix.expression.Expression;
import com.salesforce.phoenix.expression.aggregator.Aggregator;
import com.salesforce.phoenix.expression.aggregator.DistinctValueWithCountClientAggregator;
import com.salesforce.phoenix.expression.aggregator.DistinctValueWithCountServerAggregator;
import com.salesforce.phoenix.expression.aggregator.PercentileDiscClientAggregator;
import com.salesforce.phoenix.parse.FunctionParseNode.Argument;
import com.salesforce.phoenix.parse.FunctionParseNode.BuiltInFunction;
import com.salesforce.phoenix.schema.PDataType;
/**
*
* Built-in function for PERCENTILE_DISC(<expression>) WITHIN GROUP (ORDER BY <expression> ASC/DESC) aggregate function
*
* @author ramkrishna
* @since 1.2.1
*/
@BuiltInFunction(name = PercentileDiscAggregateFunction.NAME, args = { @Argument(allowedTypes = { PDataType.DECIMAL }),
@Argument(allowedTypes = { PDataType.BOOLEAN }, isConstant = true),
@Argument(allowedTypes = { PDataType.DECIMAL }, isConstant = true, minValue = "0", maxValue = "1") })
public class PercentileDiscAggregateFunction extends DistinctValueWithCountAggregateFunction {
public static final String NAME = "PERCENTILE_DISC";
public PercentileDiscAggregateFunction() {
}
public PercentileDiscAggregateFunction(List<Expression> childern) {
super(childern);
}
@Override
public Aggregator newServerAggregator(Configuration conf) {
return new DistinctValueWithCountServerAggregator(conf);
}
@Override
public DistinctValueWithCountClientAggregator newClientAggregator() {
return new PercentileDiscClientAggregator(children, getAggregatorExpression().getColumnModifier());
}
@Override
public String getName() {
return NAME;
}
}