Package io.trino.operator.aggregation.partial

Class PartialAggregationController

java.lang.Object

io.trino.operator.aggregation.partial.PartialAggregationController

public class PartialAggregationController
extends Object

Controls whenever partial aggregation is enabled across all HashAggregationOperators for a particular plan node on a single node. Partial aggregation is disabled once enough rows has been processed (minNumberOfRowsProcessed) and the ratio between output(unique) and input rows is too high (> uniqueRowsRatioThreshold). TODO https://github.com/trinodb/trino/issues/11361 add support to adaptively re-enable partial aggregation.

The class is thread safe and objects of this class are used potentially by multiple threads/drivers simultaneously. Different threads either: - modify fields via synchronized onFlush(long, long). - read volatile partialAggregationDisabled (volatile here gives visibility).

Constructor Summary

Constructors

Constructor	Description
PartialAggregationController(long minNumberOfRowsProcessedToDisable, double uniqueRowsRatioThreshold)

Method Summary

Modifier and Type	Method	Description
PartialAggregationController	duplicate()
boolean	isPartialAggregationDisabled()
void	onFlush(long rowsProcessed, long uniqueRowsProduced)

Methods inherited from class java.lang.Object

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

Constructor Details

PartialAggregationController

public PartialAggregationController(long minNumberOfRowsProcessedToDisable,
 double uniqueRowsRatioThreshold)

Method Details

isPartialAggregationDisabled

public boolean isPartialAggregationDisabled()

onFlush

public void onFlush(long rowsProcessed,
 long uniqueRowsProduced)

duplicate

public PartialAggregationController duplicate()