de.fuberlin.wiwiss.d2rq.algebra
Interface RDFRelation
- All Superinterfaces:
- TripleMaker
- All Known Implementing Classes:
- TripleRelation, UnionOverSameBase
public interface RDFRelation
- extends TripleMaker
A relation, as defined in relational algebra, plus a set of NodeMakers
attached to the relation, plus a set of TripleMakers attached to the
NodeMakers. Very much work in progress.
- Version:
- $Id: RDFRelation.java,v 1.7 2006/09/28 12:17:44 cyganiak Exp $
- Author:
- Richard Cyganiak (richard@cyganiak.de)
EMPTY
static final RDFRelation EMPTY
baseRelation
Relation baseRelation()
projectionColumns
Set projectionColumns()
isUnique
boolean isUnique()
nodeMaker
NodeMaker nodeMaker(int index)
- TODO Get rid of RDFRelation.nodeMaker(index)
- Parameters:
index
- 0, 1 or 2
- Returns:
- The subject, predicate or object NodeMaker
selectTriple
RDFRelation selectTriple(Triple triplePattern)
renameColumns
RDFRelation renameColumns(ColumnRenamer renamer)
names
Collection names()
namedNodeMaker
NodeMaker namedNodeMaker(String name)