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 after sampling sufficient amount of input and the ratio between output(unique) and input rows is too high (> uniqueRowsRatioThreshold).

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, java.util.OptionalLong). - read volatile partialAggregationDisabled (volatile here gives visibility).

Constructor Summary

Constructors

Constructor	Description
PartialAggregationController(io.airlift.units.DataSize maxPartialMemory, double uniqueRowsRatioThreshold)

Method Summary

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

Methods inherited from class java.lang.Object

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

Constructor Details

PartialAggregationController

public PartialAggregationController(io.airlift.units.DataSize maxPartialMemory,
 double uniqueRowsRatioThreshold)

Method Details

isPartialAggregationDisabled

public boolean isPartialAggregationDisabled()

onFlush

public void onFlush(long bytesProcessed,
 long rowsProcessed,
 OptionalLong uniqueRowsProduced)

duplicate

public PartialAggregationController duplicate()