## Uses of Interface
org.eclipse.rdf4j.federated.algebra.QueryRef

- Packages that use QueryRef
  Package | Description
  --- | ---
  org.eclipse.rdf4j.federated.algebra |

- - ### Uses of QueryRef in org.eclipse.rdf4j.federated.algebra

    Subinterfaces of QueryRef in org.eclipse.rdf4j.federated.algebra
    Modifier and Type | Interface | Description
    --- | --- | ---
    `interface` | `ExclusiveTupleExpr` | Interface representing nodes that can exclusively be evaluated at a single `StatementSource`.
    `interface` | `ExclusiveTupleExprRenderer` | A specialization of `ExclusiveTupleExpr` which provides definitions how the expressions can be rendered to a sub-query.
    `interface` | `FedXTupleExpr` | Interface marking known FedX algebra nodes.
    `interface` | `StatementTupleExpr` | Interface for any expression that can be evaluated

    Classes in org.eclipse.rdf4j.federated.algebra that implement QueryRef
    Modifier and Type | Class | Description
    --- | --- | ---
    `class` | `CheckStatementPattern` | A statement pattern with no free variables when provided with some particular BindingSet in evaluate.
    `class` | `EmptyNJoin` | Algebra construct representing an empty join.
    `class` | `EmptyNUnion` | Algebra construct representing an empty union.
    `class` | `ExclusiveArbitraryLengthPath` | An `ArbitraryLengthPath` node which can be evaluated at a single node.
    `class` | `ExclusiveGroup` | Represents a group of `ExclusiveTupleExpr` that can only produce results at a single endpoint, the `StatementSource`.
    `class` | `ExclusiveStatement` | Represents a StatementPattern that can only produce results at a single endpoint, the owner.
    `class` | `FederatedDescribeOperator` | Specialized `DescribeOperator` Node for maintaining `QueryInfo`.
    `class` | `FedXStatementPattern` | Base class providing all common functionality for FedX StatementPatterns
    `class` | `NJoin` | A tuple expression that represents an nary-Join.
    `class` | `NTuple` | Base class for any nary-tuple expression
    `class` | `NUnion` | A tuple expression that represents an nary-Union.
    `class` | `PassThroughTupleExpr` | Marker `TupleExpr` that is used from `FedXTupleQuery.evaluate(TupleQueryResultHandler)` to allow for passing through of results to the handler.
    `class` | `SingleSourceQuery` | A query which has a single relevant source.
    `class` | `StatementSourcePattern` | Represents statements that can produce results at a some particular endpoints, the statement sources.