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

Class FirstValueDescAggrResult

java.lang.Object

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

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

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

All Implemented Interfaces:

java.lang.Cloneable

public class FirstValueDescAggrResult
extends FirstValueAggrResult

Field Summary

Fields inherited from class org.apache.iotdb.db.query.aggregation.AggregateResult

hasCandidateResult, resultDataType, TIME_LENGTH_FOR_FIRST_VALUE, timestamp

Constructor Summary

Constructors

Constructor	Description
FirstValueDescAggrResult(org.apache.iotdb.tsfile.file.metadata.enums.TSDataType dataType)

Method Summary

Modifier and Type	Method	Description
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(org.apache.iotdb.tsfile.read.common.IBatchDataIterator batchIterator, long minBound, long maxBound)	Aggregate results cannot be calculated using Statistics directly, using the data in each page.
void	updateResultFromStatistics(org.apache.iotdb.tsfile.file.metadata.statistics.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

Methods inherited from class org.apache.iotdb.db.query.aggregation.impl.FirstValueAggrResult

deserializeSpecificFields, getResult, merge, reset, serializeSpecificFields, updateResultFromPageData

Methods inherited from class org.apache.iotdb.db.query.aggregation.AggregateResult

clone, deserializeFrom, getAggregationType, getBinaryValue, getBooleanValue, getDoubleAbsValue, getDoubleValue, getFloatAbsValue, getFloatValue, getIntAbsValue, getIntValue, getLongAbsValue, getLongValue, getResultDataType, getTime, getValue, hasCandidateResult, serialize, serializeTo, setBinaryValue, setBooleanValue, setDoubleValue, setFloatValue, setIntValue, setLongValue, setTime, setValue, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

FirstValueDescAggrResult

public FirstValueDescAggrResult(org.apache.iotdb.tsfile.file.metadata.enums.TSDataType dataType)

Method Detail

updateResultFromStatistics

public void updateResultFromStatistics(org.apache.iotdb.tsfile.file.metadata.statistics.Statistics statistics)

Description copied from class: AggregateResult

Calculate the aggregation using Statistics

Overrides:

updateResultFromStatistics in class FirstValueAggrResult

Parameters:

statistics - chunkStatistics or pageStatistics

updateResultFromPageData

public void updateResultFromPageData(org.apache.iotdb.tsfile.read.common.IBatchDataIterator batchIterator,
                                     long minBound,
                                     long maxBound)

Description copied from class: AggregateResult

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

Overrides:

updateResultFromPageData in class FirstValueAggrResult

Parameters:

batchIterator - the data in Page

minBound - calculate points whose time >= bound

maxBound - calculate points whose time < bound

updateResultUsingTimestamps

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

Description copied from class: AggregateResult

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

Overrides:

updateResultUsingTimestamps in class FirstValueAggrResult

Throws:

java.io.IOException - TsFile data read error

updateResultUsingValues

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

Description copied from class: AggregateResult

This method calculates the aggregation using values that have been calculated

Overrides:

updateResultUsingValues in class FirstValueAggrResult

isAscending

public boolean isAscending()

Description copied from class: AggregateResult

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

Overrides:

isAscending in class AggregateResult

hasFinalResult

public boolean hasFinalResult()

Description copied from class: 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.

Overrides:

hasFinalResult in class FirstValueAggrResult

Returns:

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