org.apache.flink.table.runtime.operators.aggregate

Class RecordCounter

java.lang.Object

org.apache.flink.table.runtime.operators.aggregate.RecordCounter

All Implemented Interfaces:

Serializable

public abstract class RecordCounter
extends Object
implements Serializable

The RecordCounter is used to count the number of input records under the current key.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
RecordCounter()

Method Summary

Modifier and Type	Method and Description
static RecordCounter	of(int indexOfCountStar) Creates a RecordCounter depends on the index of count(*).

Methods inherited from class java.lang.Object

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

Constructor Detail

RecordCounter

public RecordCounter()

Method Detail

of

public static RecordCounter of(int indexOfCountStar)

Creates a RecordCounter depends on the index of count(*). If index is less than zero, returns AccumulationRecordCounter, otherwise, RetractionRecordCounter.

Parameters:

indexOfCountStar - The index of COUNT(*) in the aggregates. -1 when the input doesn't contain COUNT(*), i.e. doesn't contain retraction messages. We make sure there is a COUNT(*) if input stream contains retraction.