Class PhysicalOpBindJoinSPARQL

java.lang.Object

se.liu.ida.hefquin.engine.queryplan.physical.impl.BaseForPhysicalOpSingleInputJoin

se.liu.ida.hefquin.engine.queryplan.physical.impl.PhysicalOpBindJoinSPARQL

All Implemented Interfaces:

QueryPlanOperator, PhysicalOperator, PhysicalOperatorForLogicalOperator, UnaryPhysicalOp, UnaryPhysicalOpForLogicalOp

public class PhysicalOpBindJoinSPARQL
extends BaseForPhysicalOpSingleInputJoin

A physical operator that implements a batch-based bind-join algorithm for SPARQL endpoints that can be used in different variations. The variation to be used is determined by the arguments provided to the constructor of the Factory class (see below). It is possible to use either a parallel or a sequential implementation (see BaseForExecOpParallelBindJoin vs BaseForExecOpSequentialBindJoin) and, additionally, the form of the bind-join requests can be decided (e.g., VALUES-based, FILTER-based).

Semantics: This operator implements the logical operators gpAdd (see LogicalOpGPAdd) and gpOptAdd (see LogicalOpGPOptAdd). That is, for a given graph pattern, a federation member, and an input sequence of solution mappings (produced by the sub-plan under this operator), the operator produces the solutions resulting from the join (inner or left outer) between the input solutions and the solutions of evaluating the given graph pattern over the data of the federation member.

Algorithm description: For a detailed description of the actual algorithm associated with this physical operator, refer to BaseForExecOpParallelBindJoin (for the parallel version) and to BaseForExecOpSequentialBindJoin (for the sequential version), and to ExecOpSequentialBindJoinSPARQLwithVarRenaming, ExecOpSequentialBindJoinSPARQLwithVALUES, ExecOpSequentialBindJoinSPARQLwithFILTER, ExecOpSequentialBindJoinSPARQLwithUNION, and ExecOpSequentialBindJoinSPARQLwithVALUESorFILTER, for the different kinds of bind-join requests.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	PhysicalOpBindJoinSPARQL.Factory

Field Summary

Fields

Modifier and Type	Field	Description
static final String	FILTER_BASED
protected final PhysicalOpBindJoinSPARQL.Factory	myFactory
static final Set<String>	POSSIBLE_TYPES
static final String	UNION_BASED
static final String	VALUES_BASED
static final String	VALUES_OR_FILTER
static final String	VARIABLE_RENAMING

Fields inherited from class se.liu.ida.hefquin.engine.queryplan.physical.impl.BaseForPhysicalOpSingleInputJoin

lop

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	PhysicalOpBindJoinSPARQL(LogicalOpGPAdd lop, PhysicalOpBindJoinSPARQL.Factory myFactory)
protected	PhysicalOpBindJoinSPARQL(LogicalOpGPOptAdd lop, PhysicalOpBindJoinSPARQL.Factory myFactory)

Method Summary

Modifier and Type	Method	Description
UnaryExecutableOp	createExecOp(boolean collectExceptions, QueryPlanningInfo qpInfo, ExpectedVariables... inputVars)	Creates and returns the executable operator to be used for this physical operator.
protected UnaryExecutableOp	createExecOp(SPARQLGraphPattern pattern, SPARQLEndpoint sparqlEndpoint, boolean useOuterJoinSemantics, boolean collectExceptions, QueryPlanningInfo qpInfo, ExpectedVariables... inputVars)
boolean	equals(Object o)
int	getBatchSize()
String	getType()
int	hashCode()
static boolean	hasNonJoiningVar(SPARQLGraphPattern pattern, ExpectedVariables vars)
String	toString()
boolean	usesParallelVersion()
void	visit(PhysicalPlanVisitor visitor)

Methods inherited from class se.liu.ida.hefquin.engine.queryplan.physical.impl.BaseForPhysicalOpSingleInputJoin

getLogicalOperator

Methods inherited from class java.lang.Object

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

Methods inherited from interface se.liu.ida.hefquin.engine.queryplan.physical.PhysicalOperatorForLogicalOperator

getExpectedVariables

Field Details

VALUES_BASED

public static final String VALUES_BASED

See Also:

• Constant Field Values

FILTER_BASED

public static final String FILTER_BASED

See Also:

• Constant Field Values

UNION_BASED

public static final String UNION_BASED

See Also:

• Constant Field Values

VARIABLE_RENAMING

public static final String VARIABLE_RENAMING

See Also:

• Constant Field Values

VALUES_OR_FILTER

public static final String VALUES_OR_FILTER

See Also:

• Constant Field Values

POSSIBLE_TYPES

public static final Set<String> POSSIBLE_TYPES

myFactory

protected final PhysicalOpBindJoinSPARQL.Factory myFactory

Constructor Details

PhysicalOpBindJoinSPARQL

protected PhysicalOpBindJoinSPARQL(LogicalOpGPAdd lop,
 PhysicalOpBindJoinSPARQL.Factory myFactory)

PhysicalOpBindJoinSPARQL

protected PhysicalOpBindJoinSPARQL(LogicalOpGPOptAdd lop,
 PhysicalOpBindJoinSPARQL.Factory myFactory)

Method Details

getType

public String getType()

usesParallelVersion

public boolean usesParallelVersion()

getBatchSize

public int getBatchSize()

createExecOp

public UnaryExecutableOp createExecOp(boolean collectExceptions,
 QueryPlanningInfo qpInfo,
 ExpectedVariables... inputVars)

Description copied from interface: PhysicalOperator

Creates and returns the executable operator to be used for this physical operator. The implementation of this method has to create a new ExecutableOperator object each time it is called. The given QueryPlanningInfo object is passed to the created executable operator (to be available via the ExecutableOperator.getQueryPlanningInfo() method) and should be taken from the physical plan whose root operator is this physical operator. The given collectExceptions flag is passed to the executable operator and determines whether that operator collects its exceptions (see ExecutableOperator.getExceptionsCaughtDuringExecution()) or throws them immediately. The number of ExpectedVariables objects passed as arguments to this method must be in line with the degree of this operator (e.g., for a unary operator, exactly one such object must be passed).

createExecOp

protected UnaryExecutableOp createExecOp(SPARQLGraphPattern pattern,
 SPARQLEndpoint sparqlEndpoint,
 boolean useOuterJoinSemantics,
 boolean collectExceptions,
 QueryPlanningInfo qpInfo,
 ExpectedVariables... inputVars)

visit

public void visit(PhysicalPlanVisitor visitor)

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object

hasNonJoiningVar

public static boolean hasNonJoiningVar(SPARQLGraphPattern pattern,
 ExpectedVariables vars)