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

Class PartialMatch

java.lang.Object

com.apple.foundationdb.record.query.plan.temp.PartialMatch

All Implemented Interfaces:

Bindable

public class PartialMatch
extends Object
implements Bindable

Case class to represent a partial match. A partial match is stored in a multi map in GroupExpressionRefs that are part of a query graph. A partial match is never stored in a GroupExpressionRef of a match candidate. A partial match establishes the a relation ships between a reference ref1 in a query graph and a reference ref2 in a match candidate. It should be interpreted as there is a partial match between ref1 and ref2 if ref1 is result-equivalent to ref2' under the bindings in the alias map returned by (getBoundAliasMap()) where ref2' is obtained by is applying compensation to ref2. If there is no compensation this simplifies to: there is a partial match between ref1 and ref2 if ref1 is result-equivalent to ref2 under the bindings in the alias map returned by (getBoundAliasMap()). It is the task of a matching algorithm (see CascadesPlanner) to establish PartialMatches between query graph and match candidate graphs. Once there is a partial match for the top-most reference in the match candidate, we can replace the reference on the query graph side with a scan over the match candidate's materialized version (e.g. an index) and subsequent compensation.

Constructor Summary

Constructors

Constructor	Description
PartialMatch(AliasMap boundAliasMap, MatchCandidate matchCandidate, ExpressionRef<? extends RelationalExpression> queryRef, RelationalExpression queryExpression, ExpressionRef<? extends RelationalExpression> candidateRef, MatchInfo matchInfo)

Method Summary

Modifier and Type	Method	Description
Stream<PlannerBindings>	bindTo(PlannerBindings outerBindings, ExpressionMatcher<? extends Bindable> matcher)	Attempt to match the matcher to this bindable object.
Compensation	compensate(Map<CorrelationIdentifier,ComparisonRange> boundParameterPrefixMap)
AliasMap	getBoundAliasMap()
Map<CorrelationIdentifier,ComparisonRange>	getBoundParameterPrefixMap()
ExpressionRef<? extends RelationalExpression>	getCandidateRef()
MatchCandidate	getMatchCandidate()
MatchInfo	getMatchInfo()
int	getNumBoundParameterPrefix()
RelationalExpression	getQueryExpression()
ExpressionRef<? extends RelationalExpression>	getQueryRef()
static Collection<MatchInfo>	matchesFromMap(IdentityBiMap<Quantifier,PartialMatch> partialMatchMap)

Methods inherited from class java.lang.Object

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

Constructor Detail

PartialMatch

public PartialMatch(@Nonnull
                    AliasMap boundAliasMap,
                    @Nonnull
                    MatchCandidate matchCandidate,
                    @Nonnull
                    ExpressionRef<? extends RelationalExpression> queryRef,
                    @Nonnull
                    RelationalExpression queryExpression,
                    @Nonnull
                    ExpressionRef<? extends RelationalExpression> candidateRef,
                    @Nonnull
                    MatchInfo matchInfo)

Method Detail

getBoundAliasMap

@Nonnull
public AliasMap getBoundAliasMap()

getMatchCandidate

@Nonnull
public MatchCandidate getMatchCandidate()

getQueryRef

@Nonnull
public ExpressionRef<? extends RelationalExpression> getQueryRef()

getQueryExpression

@Nonnull
public RelationalExpression getQueryExpression()

getCandidateRef

@Nonnull
public ExpressionRef<? extends RelationalExpression> getCandidateRef()

getMatchInfo

@Nonnull
public MatchInfo getMatchInfo()

getNumBoundParameterPrefix

public int getNumBoundParameterPrefix()

getBoundParameterPrefixMap

public Map<CorrelationIdentifier,ComparisonRange> getBoundParameterPrefixMap()

bindTo

@Nonnull
public Stream<PlannerBindings> bindTo(@Nonnull
                                      PlannerBindings outerBindings,
                                      @Nonnull
                                      ExpressionMatcher<? extends Bindable> matcher)

Description copied from interface: Bindable

Attempt to match the matcher to this bindable object.

Specified by:

bindTo in interface Bindable

Parameters:

outerBindings - existing bindings to be used by the matcher

matcher - the matcher to match against

Returns:

a map of bindings if the match succeeded, or an empty Optional if it failed

compensate

@Nonnull
public Compensation compensate(@Nonnull
                               Map<CorrelationIdentifier,ComparisonRange> boundParameterPrefixMap)

matchesFromMap

@Nonnull
public static Collection<MatchInfo> matchesFromMap(@Nonnull
                                                   IdentityBiMap<Quantifier,PartialMatch> partialMatchMap)