org.apache.iotdb.tsfile.read.expression.util

Class ExpressionOptimizer

java.lang.Object

org.apache.iotdb.tsfile.read.expression.util.ExpressionOptimizer

public class ExpressionOptimizer
extends Object

Method Summary

Modifier and Type	Method and Description
static ExpressionOptimizer	getInstance()
IExpression	optimize(IExpression expression, List<Path> selectedSeries) try to remove GlobalTimeExpression.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

getInstance

public static ExpressionOptimizer getInstance()

optimize

public IExpression optimize(IExpression expression,
                            List<Path> selectedSeries)
                     throws QueryFilterOptimizationException

try to remove GlobalTimeExpression.

Parameters:

expression - IExpression to be transferred

selectedSeries - selected series

Returns:

an executable query filter, whether a GlobalTimeExpression or All leaf nodes are SingleSeriesExpression

Throws:

QueryFilterOptimizationException