com.bigdata.rdf.sparql.ast

Class UnionNode

java.lang.Object

com.bigdata.bop.CoreBaseBOp

com.bigdata.bop.ModifiableBOpBase

com.bigdata.rdf.sparql.ast.ASTBase

com.bigdata.rdf.sparql.ast.QueryNodeBase

com.bigdata.rdf.sparql.ast.GroupMemberNodeBase<E>

com.bigdata.rdf.sparql.ast.GroupNodeBase<E>

com.bigdata.rdf.sparql.ast.GraphPatternGroup<JoinGroupNode>

com.bigdata.rdf.sparql.ast.UnionNode

All Implemented Interfaces:

BOp, IBindingProducerNode, IGroupMemberNode, IGroupNode<JoinGroupNode>, IJoinNode, IQueryNode, IReorderableNode, IVariableBindingRequirements, IPropertySet, Serializable, Cloneable, Iterable<JoinGroupNode>

Direct Known Subclasses:

PropertyPathUnionNode

public class UnionNode
extends GraphPatternGroup<JoinGroupNode>
implements IReorderableNode

A special kind of group IGroupNode that represents the sparql union operator.

Note: This node only accepts JoinGroupNodes as children.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class com.bigdata.rdf.sparql.ast.GraphPatternGroup

GraphPatternGroup.Annotations

Nested classes/interfaces inherited from interface com.bigdata.rdf.sparql.ast.IQueryNode

IQueryNode.Annotations

Field Summary

Fields inherited from class com.bigdata.bop.CoreBaseBOp

DEFAULT_INITIAL_CAPACITY

Fields inherited from interface com.bigdata.bop.BOp

NOANNS, NOARGS

Constructor Summary

Constructors

Constructor and Description
UnionNode()
UnionNode(BOp[] args, Map<String,Object> anns) Required shallow copy constructor.
UnionNode(UnionNode op) Constructor required for com.bigdata.bop.BOpUtility#deepCopy(FilterNode).

Method Summary

Methods

Modifier and Type	Method and Description
void	addArg(BOp newArg) Add a new argument (core mutation method).
void	addArg(int index, BOp newArg) Add a new argument (core mutation method) at the specified index.
UnionNode	addChild(JoinGroupNode child) Add a child to this group.
Set<IVariable<?>>	getDesiredBound(StaticAnalysis sa) Get variables that are not required to be bound, but desired in the sense that we want them to be bound when evaluating the construct.
long	getEstimatedCardinality(StaticOptimizer optimizer) Return the estimated cardinality - either the range count of a statement pattern or some computed estimated cardinality for a join group.
Set<IVariable<?>>	getRequiredBound(StaticAnalysis sa) Return the variables used in the node that *must* be bound prior to evaluating the node.
boolean	isMinus() Returns false.
boolean	isOptional() Returns false.
boolean	isReorderable() The decision about whether to re-order can no longer be made simply by examining the type - individual instances of a particular type may or may not be reorderable.
int	replaceWith(BOp oldChild, BOp newChild) Replace a child of a node with another reference (destructive modification).

Methods inherited from class com.bigdata.rdf.sparql.ast.GraphPatternGroup

getChildren, getJoinVars, getProjectInVars, setJoinVars, setProjectInVars

Methods inherited from class com.bigdata.rdf.sparql.ast.GroupNodeBase

clone, getAttachedJoinFilters, getChildren, isEmpty, iterator, removeArg, removeChild, setArg, setAttachedJoinFilters, size, toString

Methods inherited from class com.bigdata.rdf.sparql.ast.GroupMemberNodeBase

getContext, getParent, getParentGraphPatternGroup, getParentJoinGroup, setParent

Methods inherited from class com.bigdata.rdf.sparql.ast.QueryNodeBase

getQueryHints, toString

Methods inherited from class com.bigdata.rdf.sparql.ast.ASTBase

addExplainHint, getExplainHints, getQueryHint, getQueryHint, getQueryHintAsBoolean, getQueryHintAsBoolean, getQueryHintAsInteger, replaceAllWith, setQueryHint, setQueryHints

Methods inherited from class com.bigdata.bop.ModifiableBOpBase

addArgIfAbsent, annotations, annotationsEqual, argIterator, args, arity, clearProperty, copyAll, get, getProperty, indexOf, setArgs, setId, setProperty, setUnboundProperty, toArray, toArray

Methods inherited from class com.bigdata.bop.CoreBaseBOp

annotationsEqual, annotationsToString, annotationsToString, annotationValueToString, checkArgs, equals, getEvaluationContext, getId, getProperty, getRequiredProperty, hashCode, indent, isController, mutation, shortenName, toShortString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface com.bigdata.rdf.sparql.ast.IGroupMemberNode

getContext, getParent, getParentGraphPatternGroup, getParentJoinGroup, setParent

Methods inherited from interface com.bigdata.rdf.sparql.ast.IQueryNode

toString

Methods inherited from interface com.bigdata.bop.BOp

annotations, argIterator, args, arity, clone, get, getEvaluationContext, getId, getProperty, getRequiredProperty, isController, setProperty, toArray, toArray, toShortString, toString

Methods inherited from interface cutthecrap.utils.striterators.IPropertySet

getProperty

Methods inherited from interface com.bigdata.rdf.sparql.ast.IJoinNode

getAttachedJoinFilters, setAttachedJoinFilters

Constructor Detail

UnionNode

public UnionNode(UnionNode op)

Constructor required for com.bigdata.bop.BOpUtility#deepCopy(FilterNode).

UnionNode

public UnionNode(BOp[] args,
         Map<String,Object> anns)

Required shallow copy constructor.

UnionNode

public UnionNode()

Method Detail

addChild

public UnionNode addChild(JoinGroupNode child)

Description copied from interface: IGroupNode

Add a child to this group. Child can be a statement pattern, a filter, or another group.

Specified by:

addChild in interface IGroupNode<JoinGroupNode>

Overrides:

addChild in class GroupNodeBase<JoinGroupNode>

Returns:

this

isOptional

public final boolean isOptional()

Returns false.

Specified by:

isOptional in interface IJoinNode

isMinus

public final boolean isMinus()

Returns false.

Specified by:

isMinus in interface IJoinNode

getEstimatedCardinality

public long getEstimatedCardinality(StaticOptimizer optimizer)

Description copied from interface: IReorderableNode

Return the estimated cardinality - either the range count of a statement pattern or some computed estimated cardinality for a join group.

Specified by:

getEstimatedCardinality in interface IReorderableNode

Parameters:

optimizer - This optimizer can be used to help work out the estimate

isReorderable

public boolean isReorderable()

Description copied from interface: IReorderableNode

The decision about whether to re-order can no longer be made simply by examining the type - individual instances of a particular type may or may not be reorderable.

Specified by:

isReorderable in interface IReorderableNode

addArg

public void addArg(BOp newArg)

Description copied from class: GroupNodeBase

Add a new argument (core mutation method).

Overridden to set the parent reference on the child

Overrides:

addArg in class GroupNodeBase<JoinGroupNode>

Parameters:

newArg - The argument.

addArg

public void addArg(int index,
          BOp newArg)

Description copied from class: GroupNodeBase

Add a new argument (core mutation method) at the specified index.

Overridden to set the parent reference on the child

Overrides:

addArg in class GroupNodeBase<JoinGroupNode>

Parameters:

index - The index at which the child expression is to be inserted.

newArg - The argument.

replaceWith

public int replaceWith(BOp oldChild,
              BOp newChild)

Description copied from class: GroupNodeBase

Replace a child of a node with another reference (destructive modification). All arguments which point to the oldChild will be replaced by references to the newChild.

Overridden to set the parent reference on the new child and clear the parent reference on the old child.

Overrides:

replaceWith in class GroupNodeBase<JoinGroupNode>

Returns:

The #of references which were replaced.

getRequiredBound

public Set<IVariable<?>> getRequiredBound(StaticAnalysis sa)

Description copied from interface: IVariableBindingRequirements

Return the variables used in the node that *must* be bound prior to evaluating the node. For instance, when evaluation a SPARQL 1.1 service and the endpoint is specified through a variable, then this variable must be bound in order to identify the endpoint to which the query is to be sent. By *must* be bound we mean that, if it is possible to bring the variables in a join group in order such that they are bound when executing the construct (e.g., think of a FILTER), then we *must* consider that. However, when the IVariableBindingRequirements#getRequiredBound() interface cannot be satisified, the query may still be valid and return results (for the SPARQL 1.1 service example mentioned above, it may not, for the FILTER it may). The set of these variables must be disjoint from IVariableBindingRequirements#getRequiredUnound().

Specified by:

getRequiredBound in interface IVariableBindingRequirements

Returns:

the set of variables that must be bound prior to evaluation

getDesiredBound

public Set<IVariable<?>> getDesiredBound(StaticAnalysis sa)

Description copied from interface: IVariableBindingRequirements

Get variables that are not required to be bound, but desired in the sense that we want them to be bound when evaluating the construct. In general, the more variables are bound, the better, but this might differ for certain constructs. Should only report variables that are *not* reported through method IVariableBindingRequirements.getRequiredBound(StaticAnalysis).

Specified by:

getDesiredBound in interface IVariableBindingRequirements

Returns:

the set of variables that are desires to be bound, but not required