Class FilteredProductOptimiser

An Algebra Optimiser which implements the Filtered Product optimisation.

Inheritance

object

FilteredProductOptimiser

Implements

IAlgebraOptimiser

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Namespace: VDS.RDF.Query.Optimisation

Assembly: dotNetRdf.dll

Syntax

public class FilteredProductOptimiser : IAlgebraOptimiser

Remarks

A filtered product is implied by any query where there is a product over a join or within a BGP around which there is a Filter which contains variables from both sides of the product. So rather than computing the entire product and then applying the filter we want to push filter application into the product computation.

Properties

UnsafeOptimisation

Determines whether an Optimiser will perform algebra optimizations that are potentially unsafe at execution time.

Declaration

public bool UnsafeOptimisation { get; set; }

Property Value

Type	Description
bool

Methods

IsApplicable(SparqlQuery)

Returns that this optimiser is applicable to all queries.

Declaration

public bool IsApplicable(SparqlQuery q)

Parameters

Type	Name	Description
SparqlQuery	q	Query.

Returns

Type	Description
bool

IsApplicable(SparqlUpdateCommandSet)

Returns that this optimiser is applicable to all updates.

Declaration

public bool IsApplicable(SparqlUpdateCommandSet cmds)

Parameters

Type	Name	Description
SparqlUpdateCommandSet	cmds	Updates.

Returns

Type	Description
bool

Optimise(ISparqlAlgebra)

Optimises the Algebra to use implict joins where applicable.

Declaration

public ISparqlAlgebra Optimise(ISparqlAlgebra algebra)

Parameters

Type	Name	Description
ISparqlAlgebra	algebra	Algebra.

Returns

Type	Description
ISparqlAlgebra

Implements

IAlgebraOptimiser

Extension Methods

Extensions.ToSafeString(object)

Extensions.AsEnumerable<T>(T)