it.unibz.inf.ontop.iq.node.impl

Class ExtensionalDataNodeImpl

java.lang.Object

it.unibz.inf.ontop.iq.node.impl.QueryNodeImpl

it.unibz.inf.ontop.iq.node.impl.LeafIQTreeImpl

it.unibz.inf.ontop.iq.node.impl.DataNodeImpl<RelationPredicate>

it.unibz.inf.ontop.iq.node.impl.ExtensionalDataNodeImpl

All Implemented Interfaces:

IQTree, LeafIQTree, DataNode<RelationPredicate>, ExplicitVariableProjectionNode, ExtensionalDataNode, QueryNode, Cloneable

public class ExtensionalDataNodeImpl
extends DataNodeImpl<RelationPredicate>
implements ExtensionalDataNode

"Default" implementation for an extensional data node. Most likely (but not necessarily) will be overwritten by native query language specific implementations.

Field Summary

Fields inherited from class it.unibz.inf.ontop.iq.node.impl.LeafIQTreeImpl

iqFactory

Method Summary

Modifier and Type	Method and Description
ExtensionalDataNode	acceptNodeTransformer(HomogeneousQueryNodeTransformer transformer) "Accept" method for the "Visitor" pattern.
IQTree	acceptTransformer(IQTreeVisitingTransformer transformer)
<T> T	acceptVisitor(IQVisitor<T> visitor)
void	acceptVisitor(QueryNodeVisitor visitor) "Accept" method for the "Visitor" pattern.
IQTree	applyFreshRenaming(InjectiveVar2VarSubstitution freshRenamingSubstitution) Optimized to re-use the variable nullability.
ExtensionalDataNode	clone() See https://stackoverflow.com/questions/6837362/
VariableNullability	getVariableNullability()
com.google.common.collect.ImmutableSet<com.google.common.collect.ImmutableSet<Variable>>	inferUniqueConstraints() NOT guaranteed to return all the unique constraints (MAY BE INCOMPLETE) Set of sets of determinants
boolean	isDistinct() Is distinct if it has at least one unique constraint
boolean	isEquivalentTo(QueryNode queryNode) Is syntactically equivalent
boolean	isSyntacticallyEquivalentTo(QueryNode node) TODO: explain
boolean	isVariableNullable(IntermediateQuery query, Variable variable) Returns true if it cannot guarantee the projected variable to be non-null Throws an IllegalArgumentException if the variable is not projected by the node
ExtensionalDataNode	newAtom(DataAtom<RelationPredicate> newAtom) Returns a new DataNode of the same type that will use the new atom
String	toString()
void	validate()

Methods inherited from class it.unibz.inf.ontop.iq.node.impl.DataNodeImpl

applyDescendingSubstitutionWithoutOptimizing, getKnownVariables, getLocallyDefinedVariables, getLocallyRequiredVariables, getLocalVariables, getProjectionAtom, getRequiredVariables, getVariables, isDeclaredAsEmpty

Methods inherited from class it.unibz.inf.ontop.iq.node.impl.LeafIQTreeImpl

applyDescendingSubstitution, getChildren, getPossibleVariableDefinitions, getRootNode, isConstructed, isEquivalentTo, liftIncompatibleDefinitions, normalizeForOptimization, propagateDownConstraint, removeDistincts, replaceSubTree

Methods inherited from class java.lang.Object

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

Methods inherited from interface it.unibz.inf.ontop.iq.node.DataNode

getProjectionAtom

Methods inherited from interface it.unibz.inf.ontop.iq.LeafIQTree

getRootNode

Methods inherited from interface it.unibz.inf.ontop.iq.IQTree

applyDescendingSubstitution, applyDescendingSubstitutionWithoutOptimizing, getChildren, getKnownVariables, getPossibleVariableDefinitions, getVariables, isConstructed, isDeclaredAsEmpty, isEquivalentTo, isLeaf, liftIncompatibleDefinitions, normalizeForOptimization, propagateDownConstraint, removeDistincts, replaceSubTree

Methods inherited from interface it.unibz.inf.ontop.iq.node.ExplicitVariableProjectionNode

getVariables

Methods inherited from interface it.unibz.inf.ontop.iq.node.QueryNode

getLocallyDefinedVariables, getLocallyRequiredVariables, getLocalVariables, getRequiredVariables

Method Detail

acceptVisitor

public void acceptVisitor(QueryNodeVisitor visitor)

Description copied from interface: QueryNode

"Accept" method for the "Visitor" pattern. To be implemented by leaf classes.

Specified by:

acceptVisitor in interface QueryNode

clone

public ExtensionalDataNode clone()

Description copied from class: QueryNodeImpl

See https://stackoverflow.com/questions/6837362/

Specified by:

clone in interface ExtensionalDataNode

Specified by:

clone in interface QueryNode

Overrides:

clone in class QueryNodeImpl

acceptNodeTransformer

public ExtensionalDataNode acceptNodeTransformer(HomogeneousQueryNodeTransformer transformer)
                                          throws QueryNodeTransformationException

Description copied from interface: QueryNode

"Accept" method for the "Visitor" pattern. To be implemented by leaf classes. If the transformation cannot be done, throw a QueryNodeTransformationException

Specified by:

acceptNodeTransformer in interface LeafIQTree

Specified by:

acceptNodeTransformer in interface ExtensionalDataNode

Specified by:

acceptNodeTransformer in interface QueryNode

Throws:

QueryNodeTransformationException

newAtom

public ExtensionalDataNode newAtom(DataAtom<RelationPredicate> newAtom)

Description copied from interface: DataNode

Returns a new DataNode of the same type that will use the new atom

Specified by:

newAtom in interface DataNode<RelationPredicate>

Specified by:

newAtom in interface ExtensionalDataNode

isVariableNullable

public boolean isVariableNullable(IntermediateQuery query,
                                  Variable variable)

Description copied from interface: QueryNode

Returns true if it cannot guarantee the projected variable to be non-null Throws an IllegalArgumentException if the variable is not projected by the node

Specified by:

isVariableNullable in interface QueryNode

acceptTransformer

public IQTree acceptTransformer(IQTreeVisitingTransformer transformer)

Specified by:

acceptTransformer in interface IQTree

isDistinct

public boolean isDistinct()

Is distinct if it has at least one unique constraint

Specified by:

isDistinct in interface IQTree

acceptVisitor

public <T> T acceptVisitor(IQVisitor<T> visitor)

Specified by:

acceptVisitor in interface IQTree

applyFreshRenaming

public IQTree applyFreshRenaming(InjectiveVar2VarSubstitution freshRenamingSubstitution)

Optimized to re-use the variable nullability. Useful the data node has a lot of columns.

Specified by:

applyFreshRenaming in interface IQTree

getVariableNullability

public VariableNullability getVariableNullability()

Specified by:

getVariableNullability in interface IQTree

validate

public void validate()
              throws InvalidIntermediateQueryException

Specified by:

validate in interface IQTree

Throws:

InvalidIntermediateQueryException

inferUniqueConstraints

public com.google.common.collect.ImmutableSet<com.google.common.collect.ImmutableSet<Variable>> inferUniqueConstraints()

Description copied from interface: IQTree

NOT guaranteed to return all the unique constraints (MAY BE INCOMPLETE) Set of sets of determinants

Specified by:

inferUniqueConstraints in interface IQTree

isSyntacticallyEquivalentTo

public boolean isSyntacticallyEquivalentTo(QueryNode node)

Description copied from interface: QueryNode

TODO: explain

Specified by:

isSyntacticallyEquivalentTo in interface QueryNode

isEquivalentTo

public boolean isEquivalentTo(QueryNode queryNode)

Description copied from interface: QueryNode

Is syntactically equivalent

Specified by:

isEquivalentTo in interface QueryNode

toString

public String toString()

Overrides:

toString in class Object