RecordCounter (Flink : Table : Runtime 1.18.1-cp2 API)

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 Description

RecordCounter()

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method	Description
`static RecordCounter`	`of(int indexOfCountStar)`	Creates a `RecordCounter` depends on the index of count(*).
`abstract boolean`	`recordCountIsZero(org.apache.flink.table.data.RowData acc)`	We store the counter in the accumulator.

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
  - recordCountIsZero
```
public abstract boolean recordCountIsZero(org.apache.flink.table.data.RowData acc)
```
    We store the counter in the accumulator. If the counter is not zero, which means we aggregated at least one record for current key.
    
    Returns:
    
    true if input record count is zero, false if not.
  - of
```
public static RecordCounter of(int indexOfCountStar)
```
    Creates a RecordCounter depends on the index of count(*). If index is less than zero, returns RecordCounter.AccumulationRecordCounter, otherwise, RecordCounter.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.