com.facebook.presto.spi.statistics

Interface HistoryBasedPlanStatisticsProvider

All Known Implementing Classes:

EmptyPlanStatisticsProvider

public interface HistoryBasedPlanStatisticsProvider

An interface to provide plan statistics from an external source to Presto planner. A simple implementation can be a key value store using provided canonical plan hashes of plan nodes. More advanced implementations can parse the PlanNode, and predict statistics.

Method Summary

Modifier and Type	Method and Description
String	getName()
Map<PlanNodeWithHash,HistoricalPlanStatistics>	getStats(List<PlanNodeWithHash> planNodesWithHash) 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.

Method Detail

getName

String getName()

getStats

Map<PlanNodeWithHash,HistoricalPlanStatistics> getStats(List<PlanNodeWithHash> planNodesWithHash)

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.

putStats

void putStats(Map<PlanNodeWithHash,HistoricalPlanStatistics> hashesAndStatistics)

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