io.prestosql.sql.planner.iterative.rule

Class PruneCountAggregationOverScalar

java.lang.Object

io.prestosql.sql.planner.iterative.rule.PruneCountAggregationOverScalar

All Implemented Interfaces:

Rule<AggregationNode>

public class PruneCountAggregationOverScalar
extends Object
implements Rule<AggregationNode>

A count over a subquery can be reduced to a VALUES(1) provided the subquery is a scalar

Nested Class Summary

Nested classes/interfaces inherited from interface io.prestosql.sql.planner.iterative.Rule

Rule.Context, Rule.Result

Constructor Summary

Constructors

Constructor and Description
PruneCountAggregationOverScalar()

Method Summary

Modifier and Type	Method and Description
Rule.Result	apply(AggregationNode parent, Captures captures, Rule.Context context)
Pattern<AggregationNode>	getPattern() Returns a pattern to which plan nodes this rule applies.

Methods inherited from class java.lang.Object

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

Methods inherited from interface io.prestosql.sql.planner.iterative.Rule

isEnabled

Constructor Detail

PruneCountAggregationOverScalar

public PruneCountAggregationOverScalar()

Method Detail

getPattern

public Pattern<AggregationNode> getPattern()

Description copied from interface: Rule

Returns a pattern to which plan nodes this rule applies.

Specified by:

getPattern in interface Rule<AggregationNode>

apply

public Rule.Result apply(AggregationNode parent,
                         Captures captures,
                         Rule.Context context)

Specified by:

apply in interface Rule<AggregationNode>