dotNetRDF API Documentation

VDS.RDF.Query.Algebra Namespace

Contains the classes which model the mapping of SPARQL queries into the SPARQL Algebra. This namespace is a key component of the new Leviathan SPARQL engine introduced in the 0.2.x builds of dotNetRDF

Namespace Hierarchy

Classes

Class Description
AlgebraExtensions Static Helper class containing extensions used in the Algebra evaluation process
Ask Represents the Ask step of Query Evaluation
AskAnyTriples Special Algebra Construct for optimising queries of the form ASK WHERE {?s ?p ?o}
AskBgp Represents a BGP which is a set of Triple Patterns
AskUnion Represents a Union
BaseArbitraryLengthPathOperator Abstract Base Class for Arbitrary Length Path Operators
BaseMultiset Abstract Base Class for representing Multisets
BasePathOperator Abstract Base Class for Path Operators
BaseSet Abstract Base Class for implementations of the ISet interface
Bgp Represents a BGP which is a set of Triple Patterns
Bindings Represents a BINDINGS modifier on a SPARQL Query
Distinct Represents a Distinct modifier on a SPARQL Query
ExistsJoin Represents a LeftJoin predicated on the existence/non-existence of joinable sets on the RHS for each item on the LHS
Extend Represents an Extend operation which is the formal algebraic form of the BIND operation
Filter Represents a Filter
FilteredProduct Algebra operator which combines a Filter and a Product into a single operation for improved performance and reduced memory usage
FullTextQuery Algebra Operator which provides full text query capabilities for a query
Graph Represents a GRAPH clause
GroupBy Represents a Grouping
GroupMultiset Multiset which represents a Grouping of Sets from another Multiset
Having Represents a Having Clause
IdentityFilter Represents a special case Filter where the Filter restricts a variable to just one value i.e. FILTER(?x = <value>)
IdentityMultiset Represents the Identity Multiset
Join Represents a Join
LazyBgp Represents a BGP which is a set of Triple Patterns
LazyUnion Represents a Union
LeftJoin Represents a LeftJoin predicated on an arbitrary filter expression
Minus Represents the Minus join
Multiset Represents a Multiset of possible solutions
NegatedPropertySet Represents a Negated Property Set in the SPARQL Algebra
NullMultiset Represents a Multiset when there are no possible Solutions
NullOperator Represents a part of the algebra that has been determined to not return any results in advance and so can be replaced with this operator which always returns null
OneOrMorePath Represents a One or More Path (e.g. rdf:type+) in the SPARQL Algebra
OrderBy Represents an Order By clause
ParallelJoin Represents a Join which will be evaluated in parallel
ParallelUnion Represents a Union which will be evaluated in parallel
PartitionedMultiset Implementation of a multiset which is suitable for multiple threads to write to in parallel, useful for parallelizing certain operations
PropertyFunction Algebra that represents the application of a Property Function
PropertyPath Represents an arbitrary property path in the algebra (only used when strict algebra is generated)
Reduced Represents a Reduced modifier on a SPARQL Query
SameTermFilter Represents a special case Filter where the Filter is supposed to restrict a variable to just one value i.e. FILTER(SAMETERM(?x, <value>))
Select Represents the Selection step of Query Evaluation
SelectDistinctGraphs Special Algebra Construct for optimising queries of the form SELECT DISTINCT ?g WHERE {GRAPH ?g {?s ?p ?o}}
Service Represents a Service Clause
Set Represents one possible set of values which is a solution to the query
SetDistinctnessComparer Comparer for checking whether sets are distinct, check may either be using the entire set or by using only a subset of variables
SingleValueRestrictionFilter Abstract Base Class for specialised Filters which restrict the value of a variable to a single value
Slice Represents the Slice Operation in the SPARQL Algebra
SubQuery Represents a sub-query as an Algebra operator (only used when strict algebra is generated)
Table Represents a fixed set of solutions
Union Represents a Union
VariableRestrictionFilter Abstract Base Class for specialised Filters which restrict the value of a variable to some values
ZeroLengthPath Represents a Zero Length Path in the SPARQL Algebra
ZeroOrMorePath Represents a Zero or More Path in the SPARQL Algebra

Interfaces

Interface Description
IAbstractJoin Represents an Algebra construct which is an Abstract Join (i.e. any kind of Join over two algebra operators)
IBgp Represents an Algebra construct which is a BGP
IExistsJoin Represents an Algebra construct which is an Exists Join
IFilter Represents an Algebra construct which is a Filter
IJoin Represents an Algebra construct which is a Join
ILeftJoin Represents an Algebra construct which is a Left Join
IMinus Represents an Algebra construct which is a Minus
IPathOperator Interface for Property Path Operators
ISet Interface for Sets which represents a possible solution during SPARQL evaluation
ISparqlAlgebra Interface for classes that represent the SPARQL Algebra and are used to evaluate queries
ITerminalOperator Marker Interface for SPARQL Algebra constructs which are terminal operators i.e. they contain no inner algebra operators
IUnaryOperator Interface for SPARQL Algebra constructs which are unary operators i.e. they apply over a single inner Algebra
IUnion Represents an Algebra construct which is a Union