Package de.fuberlin.wiwiss.d2rq.algebra

Implementation of an RDF-based relational algebra.

See: Description

Interface Summary

Interface	Description
ProjectionSpec	Something to be used in the SELECT clause of a SQL query, e.g.
RelationalOperators

Class Summary

Class	Description
AliasMap	A map from table names to aliases.
AliasMap.Alias
Attribute	A database column.
ColumnRenamer	Something that can rename columns in various objects.
ColumnRenamerMap	A ColumnRenamer based on a fixed map of original and replacement columns.
CompatibleRelationGroup	A group of Relations that can be combined into a single relation without changing the semantics of NodeMakers.
ExpressionProjectionSpec
Join	Represents an SQL join between two tables, spanning one or more columns.
JoinOptimizer	Removes unnecessary joins from a TripleRelation in cases where this is possible without affecting the result.
MutableRelation	Wraps a relation and allows it to be modified by relational operators.
NodeRelation	A Relation associated with a number of named NodeMakers.
OrderSpec
Relation	TODO Describe this type TODO Add uniqueConstraints() TODO Explicitly list tables!!!
RelationImpl
RelationName	A relation name, including an optional schema name.
TripleRelation	A collection of virtual triples obtained by applying a Relation to a database, and applying NodeMakers for subject, predicate and object to each result row.
VariableConstraints	A map from variables to NodeMakers that helps to build up constraints in cases where a variable is bound multiple times.

Package de.fuberlin.wiwiss.d2rq.algebra Description

Implementation of an RDF-based relational algebra.