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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.MaxAggregator;
import com.salesforce.phoenix.parse.FunctionParseNode.Argument;
import com.salesforce.phoenix.parse.FunctionParseNode.BuiltInFunction;
import com.salesforce.phoenix.parse.MaxAggregateParseNode;
import com.salesforce.phoenix.schema.ColumnModifier;
import com.salesforce.phoenix.schema.PDataType;
/**
* Built-in function for finding MAX.
*
* @author syyang
* @since 0.1
*/
@BuiltInFunction(name=MaxAggregateFunction.NAME, nodeClass=MaxAggregateParseNode.class, args= {@Argument()} )
public class MaxAggregateFunction extends MinAggregateFunction {
public static final String NAME = "MAX";
public MaxAggregateFunction() {
}
public MaxAggregateFunction(List<Expression> childExpressions, CountAggregateFunction delegate) {
super(childExpressions, delegate);
}
@Override
public Aggregator newServerAggregator(Configuration conf) {
final PDataType type = getAggregatorExpression().getDataType();
ColumnModifier columnModifier = getAggregatorExpression().getColumnModifier();
return new MaxAggregator(columnModifier) {
@Override
public PDataType getDataType() {
return type;
}
};
}
@Override
public String getName() {
return NAME;
}
@Override
public ColumnModifier getColumnModifier() {
return getAggregatorExpression().getColumnModifier();
}
}