com.facebook.presto.spi.statistics

Class EmptyPlanStatisticsProvider

java.lang.Object

com.facebook.presto.spi.statistics.EmptyPlanStatisticsProvider

All Implemented Interfaces:

HistoryBasedPlanStatisticsProvider

public class EmptyPlanStatisticsProvider
extends Object
implements HistoryBasedPlanStatisticsProvider

Constructor Summary

Constructors

Constructor and Description
EmptyPlanStatisticsProvider()

Method Summary

Modifier and Type	Method and Description
static EmptyPlanStatisticsProvider	getInstance()
String	getName()
Map<PlanNodeWithHash,HistoricalPlanStatistics>	getStats(List<PlanNodeWithHash> planNodeHashes) Given a list of plan node hashes, returns historical statistics for them.
void	putStats(Map<PlanNodeWithHash,HistoricalPlanStatistics> hashesAndStatistics) Given plan hashes and corresponding statistics after a query is run, store them for future retrieval.

Methods inherited from class java.lang.Object

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

Constructor Detail

EmptyPlanStatisticsProvider

public EmptyPlanStatisticsProvider()

Method Detail

getName

public String getName()

Specified by:

getName in interface HistoryBasedPlanStatisticsProvider

getStats

public Map<PlanNodeWithHash,HistoricalPlanStatistics> getStats(List<PlanNodeWithHash> planNodeHashes)

Description copied from interface: HistoryBasedPlanStatisticsProvider

Given a list of plan node hashes, returns historical statistics for them. Some entries in return value may be missing if no corresponding history exists. This can be called even when hash of a plan node is not present. TODO: Using PlanNode as map key can be expensive, we can use Plan node id as a map key.

Specified by:

getStats in interface HistoryBasedPlanStatisticsProvider

putStats

public void putStats(Map<PlanNodeWithHash,HistoricalPlanStatistics> hashesAndStatistics)

Description copied from interface: HistoryBasedPlanStatisticsProvider

Given plan hashes and corresponding statistics after a query is run, store them for future retrieval.

Specified by:

putStats in interface HistoryBasedPlanStatisticsProvider

getInstance

public static EmptyPlanStatisticsProvider getInstance()