Package io.prestosql.sql.planner.sanity

Class ValidateAggregationsWithDefaultValues

java.lang.Object

io.prestosql.sql.planner.sanity.ValidateAggregationsWithDefaultValues

All Implemented Interfaces:

PlanSanityChecker.Checker

public class ValidateAggregationsWithDefaultValues
extends Object
implements PlanSanityChecker.Checker

When an aggregation has an empty grouping set then a default value needs to be returned in the output (e.g: 0 for COUNT(*)). In case if the aggregation is split into FINAL and PARTIAL, then default values are produced by PARTIAL aggregations. In order for the default values not to be duplicated, FINAL aggregation needs to be separated from PARTIAL aggregation by a remote repartition exchange or the FINAL aggregation needs to be executed on a single node. In case both FINAL and PARTIAL aggregations are executed on a single node, then those need to separated by a local repartition exchange or the FINAL aggregation needs to be executed in a single thread.

Constructor Summary

Constructors

Constructor	Description
ValidateAggregationsWithDefaultValues(boolean forceSingleNode)

Method Summary

Modifier and Type	Method	Description
void	validate(PlanNode planNode, Session session, Metadata metadata, TypeOperators typeOperators, TypeAnalyzer typeAnalyzer, TypeProvider types, WarningCollector warningCollector)

Methods inherited from class java.lang.Object

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

Constructor Detail

ValidateAggregationsWithDefaultValues

public ValidateAggregationsWithDefaultValues(boolean forceSingleNode)

Method Detail

validate

public void validate(PlanNode planNode,
                     Session session,
                     Metadata metadata,
                     TypeOperators typeOperators,
                     TypeAnalyzer typeAnalyzer,
                     TypeProvider types,
                     WarningCollector warningCollector)

Specified by:

validate in interface PlanSanityChecker.Checker