Package com.apple.foundationdb.record.query.plan.temp.expressions

Class LogicalDistinctExpression

java.lang.Object

com.apple.foundationdb.record.query.plan.temp.expressions.LogicalDistinctExpression

All Implemented Interfaces:

Bindable, Correlated<RelationalExpression>, RelationalExpressionWithChildren, RelationalExpression

@API(EXPERIMENTAL)
public class LogicalDistinctExpression
extends Object
implements RelationalExpressionWithChildren

A relational planner expression representing a stream of unique records. This expression has a single child which is also a RelationalExpression. This expression represents this underlying expression with its result set de-duplicated.

See Also:

for the fallback implementation

Nested Class Summary

Nested classes/interfaces inherited from interface com.apple.foundationdb.record.query.plan.temp.Correlated

Correlated.BoundEquivalence

Nested classes/interfaces inherited from interface com.apple.foundationdb.record.query.plan.temp.RelationalExpression

RelationalExpression.CombineFunction<R,S>, RelationalExpression.CombinePredicate

Constructor Summary

Constructors

Constructor	Description
LogicalDistinctExpression(ExpressionRef<RelationalExpression> innerRef)
LogicalDistinctExpression(Quantifier inner)
LogicalDistinctExpression(RelationalExpression inner)

Method Summary

Modifier and Type	Method	Description
boolean	equals(Object other)
boolean	equalsWithoutChildren(RelationalExpression otherExpression, AliasMap equivalences)
Set<CorrelationIdentifier>	getCorrelatedToWithoutChildren()
List<? extends Quantifier>	getQuantifiers()	Return an iterator of references to the children of this planner expression.
int	getRelationalChildCount()
int	hashCode()
int	hashCodeWithoutChildren()
LogicalDistinctExpression	rebase(AliasMap translationMap)	Rebases this and all other objects this objects is composed of using a given translation map.
LogicalDistinctExpression	rebaseWithRebasedQuantifiers(AliasMap translationMap, List<Quantifier> rebasedChildren)

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.apple.foundationdb.record.query.plan.temp.RelationalExpression

acceptPropertyVisitor, adjustMatch, bindIdentities, bindTo, canCorrelate, compensate, enumerateUnboundCorrelatedTo, exactlySubsumedBy, findMatches, getResultValues, hasIncompatibleBoundQuantifiers, hasUnboundQuantifiers, match, match, semanticEquals, semanticEquals, semanticHashCode, show, subsumedBy

Methods inherited from interface com.apple.foundationdb.record.query.plan.temp.expressions.RelationalExpressionWithChildren

getCorrelatedTo

Constructor Detail

LogicalDistinctExpression

public LogicalDistinctExpression(@Nonnull
                                 RelationalExpression inner)

LogicalDistinctExpression

public LogicalDistinctExpression(@Nonnull
                                 ExpressionRef<RelationalExpression> innerRef)

LogicalDistinctExpression

public LogicalDistinctExpression(@Nonnull
                                 Quantifier inner)

Method Detail

getRelationalChildCount

public int getRelationalChildCount()

Specified by:

getRelationalChildCount in interface RelationalExpressionWithChildren

getQuantifiers

@Nonnull
public List<? extends Quantifier> getQuantifiers()

Description copied from interface: RelationalExpression

Return an iterator of references to the children of this planner expression. The iterators returned by different calls are guaranteed to be independent (i.e., advancing one will not advance another). However, they might point to the same object, as when Collections.emptyIterator() is returned. The returned iterator should be treated as an immutable object and may throw an exception if Iterator.remove() is called. The iterator must return its elements in a consistent order.

Specified by:

getQuantifiers in interface RelationalExpression

Returns:

an iterator of references to the children of this planner expression

getCorrelatedToWithoutChildren

@Nonnull
public Set<CorrelationIdentifier> getCorrelatedToWithoutChildren()

Specified by:

getCorrelatedToWithoutChildren in interface RelationalExpressionWithChildren

rebase

@Nonnull
public LogicalDistinctExpression rebase(@Nonnull
                                        AliasMap translationMap)

Description copied from interface: Correlated

Rebases this and all other objects this objects is composed of using a given translation map.

Specified by:

rebase in interface Correlated<RelationalExpression>

Specified by:

rebase in interface RelationalExpressionWithChildren

Parameters:

translationMap - a map defining a translation from CorrelationIdentifiers ids to CorrelationIdentifiers ids'. After the rebase, every correlation to an id contained ids that is contained or referred to directly or indirectly by this must have been transformed to use the mapped counterpart of id id' in ids'. IDs not contained in the translation map must remain unmodified by the rebase operation.

Returns:

a new entity that has been rebased

rebaseWithRebasedQuantifiers

@Nonnull
public LogicalDistinctExpression rebaseWithRebasedQuantifiers(@Nonnull
                                                              AliasMap translationMap,
                                                              @Nonnull
                                                              List<Quantifier> rebasedChildren)

Specified by:

rebaseWithRebasedQuantifiers in interface RelationalExpressionWithChildren

equalsWithoutChildren

public boolean equalsWithoutChildren(@Nonnull
                                     RelationalExpression otherExpression,
                                     @Nonnull
                                     AliasMap equivalences)

Specified by:

equalsWithoutChildren in interface RelationalExpression

equals

public boolean equals(Object other)

Overrides:

equals in class Object

hashCodeWithoutChildren

public int hashCodeWithoutChildren()

Specified by:

hashCodeWithoutChildren in interface RelationalExpression

hashCode

public int hashCode()

Overrides:

hashCode in class Object