org.apache.iotdb.db.query.aggregation.impl

类 LastValueDescAggrResult

java.lang.Object

org.apache.iotdb.db.query.aggregation.AggregateResult

org.apache.iotdb.db.query.aggregation.impl.LastValueAggrResult

org.apache.iotdb.db.query.aggregation.impl.LastValueDescAggrResult

public class LastValueDescAggrResult
extends LastValueAggrResult

字段概要

从类继承的字段 org.apache.iotdb.db.query.aggregation.impl.LastValueAggrResult

timestamp

从类继承的字段 org.apache.iotdb.db.query.aggregation.AggregateResult

hasCandidateResult, resultDataType, TIME_LENGTH_FOR_FIRST_VALUE

构造器概要

构造器

构造器和说明
LastValueDescAggrResult(TSDataType dataType)

方法概要

限定符和类型	方法和说明
boolean	hasFinalResult() Judge if aggregation results have been calculated.
boolean	isAscending() Whether the AggregationResult accepts data in time ascending order, if it returns false, the data should be passed in time descending order.
void	updateResultFromPageData(IBatchDataIterator batchIterator, Predicate<Long> boundPredicate) Aggregate results cannot be calculated using Statistics directly, using the data in each page.
void	updateResultFromStatistics(Statistics statistics) Calculate the aggregation using Statistics
void	updateResultUsingTimestamps(long[] timestamps, int length, IReaderByTimestamp dataReader) This method calculates the aggregation using common timestamps of the cross series filter.
void	updateResultUsingValues(long[] timestamps, int length, ValueIterator valueIterator) This method calculates the aggregation using values that have been calculated

从类继承的方法 org.apache.iotdb.db.query.aggregation.impl.LastValueAggrResult

deserializeSpecificFields, getResult, merge, reset, serializeSpecificFields, updateResultFromPageData

从类继承的方法 org.apache.iotdb.db.query.aggregation.AggregateResult

deserializeFrom, getAggregationType, getBinaryValue, getBooleanValue, getDoubleValue, getFloatValue, getIntValue, getLongValue, getResultDataType, getValue, hasCandidateResult, serializeTo, setBinaryValue, setBooleanValue, setDoubleValue, setFloatValue, setIntValue, setLongValue, setValue, toString

从类继承的方法 java.lang.Object

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

构造器详细资料

LastValueDescAggrResult

public LastValueDescAggrResult(TSDataType dataType)

方法详细资料

updateResultFromStatistics

public void updateResultFromStatistics(Statistics statistics)

从类复制的说明: AggregateResult

Calculate the aggregation using Statistics

覆盖:

updateResultFromStatistics 在类中 LastValueAggrResult

参数:

statistics - chunkStatistics or pageStatistics

updateResultFromPageData

public void updateResultFromPageData(IBatchDataIterator batchIterator,
                                     Predicate<Long> boundPredicate)

从类复制的说明: AggregateResult

Aggregate results cannot be calculated using Statistics directly, using the data in each page. This method is used in GROUP BY aggregation query.

覆盖:

updateResultFromPageData 在类中 LastValueAggrResult

参数:

batchIterator - the data in Page

boundPredicate - used to judge whether the current timestamp is out of time range, returns true if it is.

updateResultUsingTimestamps

public void updateResultUsingTimestamps(long[] timestamps,
                                        int length,
                                        IReaderByTimestamp dataReader)
                                 throws IOException

从类复制的说明: AggregateResult

This method calculates the aggregation using common timestamps of the cross series filter.

覆盖:

updateResultUsingTimestamps 在类中 LastValueAggrResult

抛出:

IOException - TsFile data read error

updateResultUsingValues

public void updateResultUsingValues(long[] timestamps,
                                    int length,
                                    ValueIterator valueIterator)

从类复制的说明: AggregateResult

This method calculates the aggregation using values that have been calculated

覆盖:

updateResultUsingValues 在类中 LastValueAggrResult

hasFinalResult

public boolean hasFinalResult()

从类复制的说明: AggregateResult

Judge if aggregation results have been calculated. In other words, if the aggregated result does not need to compute the remaining data, it returns true.

覆盖:

hasFinalResult 在类中 LastValueAggrResult

返回:

If the aggregation result has been calculated return true, else return false.

isAscending

public boolean isAscending()

从类复制的说明: AggregateResult

Whether the AggregationResult accepts data in time ascending order, if it returns false, the data should be passed in time descending order.

覆盖:

isAscending 在类中 AggregateResult