org.aksw.sparqlify.views.transform

Class ViewRewriter

java.lang.Object

org.aksw.sparqlify.views.transform.ViewRewriter

public class ViewRewriter
extends Object

Given a query, a set of views, and a set of bindings, rewrites the query using the views. Essentially what happens it this stage is that quads in the query are replaced with view: LeftJoin({a, b, c}, {x, y ,z}) becomes something like VarMap(LeftJoin(View(id, quadPattern, patternVarsToOriginal), View(id, quadPattern) , etc... ) id: Id of the view quadPattern: The specific quad pattern from the view (with variables replaced according to the binding). The overall VapMap maps each of the variables back to a varible of the query. The probably most important problem which needs to be solved is how to create the join conditions on the SQL level from bindings. - A single sparql variable may correspond to (multiple) columns in multiple table instances (-> alias) within a SQL query. - The aliases

Author:

raven ?s = Uri(concat('prefix', id)) Determining join conditions: Whenever there exists an expression such as (not) equals(?s, ?x), and the corresponding variables belong to different view instances, then the expression can be turned into a join condition.

Constructor Summary

Constructors

Constructor and Description
ViewRewriter()

Method Summary

Methods

Modifier and Type	Method and Description
SqlNodeOld	rewrite(ColRelGenerator generator, com.hp.hpl.jena.sparql.algebra.op.OpDisjunction op)
SqlNodeOld	rewrite(ColRelGenerator generator, com.hp.hpl.jena.sparql.algebra.op.OpDistinct op)
SqlNodeOld	rewrite(ColRelGenerator generator, com.hp.hpl.jena.sparql.algebra.op.OpExtend op)
SqlNodeOld	rewrite(ColRelGenerator generator, com.hp.hpl.jena.sparql.algebra.op.OpFilter filter)
SqlNodeOld	rewrite(ColRelGenerator generator, OpFilterIndexed filter)
SqlNodeOld	rewrite(ColRelGenerator generator, com.hp.hpl.jena.sparql.algebra.op.OpGroup op)
SqlNodeOld	rewrite(ColRelGenerator generator, com.hp.hpl.jena.sparql.algebra.op.OpJoin op)
SqlNodeOld	rewrite(ColRelGenerator generator, com.hp.hpl.jena.sparql.algebra.op.OpLeftJoin op)
SqlNodeOld	rewrite(ColRelGenerator generator, com.hp.hpl.jena.sparql.algebra.op.OpOrder order)
SqlNodeOld	rewrite(ColRelGenerator generator, com.hp.hpl.jena.sparql.algebra.op.OpProject op)
SqlNodeOld	rewrite(ColRelGenerator generator, OpRdfViewPattern op)
SqlNodeOld	rewrite(ColRelGenerator generator, com.hp.hpl.jena.sparql.algebra.op.OpSlice op)
SqlNodeOld	rewriteMM(ColRelGenerator generator, com.hp.hpl.jena.sparql.algebra.Op op)
SqlNodeOld	rewriteMM(com.hp.hpl.jena.sparql.algebra.Op op)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ViewRewriter

public ViewRewriter()

Method Detail

rewrite

public SqlNodeOld rewrite(ColRelGenerator generator,
                 com.hp.hpl.jena.sparql.algebra.op.OpLeftJoin op)

rewrite

public SqlNodeOld rewrite(ColRelGenerator generator,
                 com.hp.hpl.jena.sparql.algebra.op.OpDisjunction op)

rewrite

public SqlNodeOld rewrite(ColRelGenerator generator,
                 OpRdfViewPattern op)

rewrite

public SqlNodeOld rewrite(ColRelGenerator generator,
                 com.hp.hpl.jena.sparql.algebra.op.OpJoin op)

rewrite

public SqlNodeOld rewrite(ColRelGenerator generator,
                 com.hp.hpl.jena.sparql.algebra.op.OpDistinct op)

rewrite

public SqlNodeOld rewrite(ColRelGenerator generator,
                 com.hp.hpl.jena.sparql.algebra.op.OpSlice op)

rewrite

public SqlNodeOld rewrite(ColRelGenerator generator,
                 OpFilterIndexed filter)

rewrite

public SqlNodeOld rewrite(ColRelGenerator generator,
                 com.hp.hpl.jena.sparql.algebra.op.OpFilter filter)

rewrite

public SqlNodeOld rewrite(ColRelGenerator generator,
                 com.hp.hpl.jena.sparql.algebra.op.OpProject op)

rewrite

public SqlNodeOld rewrite(ColRelGenerator generator,
                 com.hp.hpl.jena.sparql.algebra.op.OpGroup op)

rewrite

public SqlNodeOld rewrite(ColRelGenerator generator,
                 com.hp.hpl.jena.sparql.algebra.op.OpOrder order)

rewriteMM

public SqlNodeOld rewriteMM(com.hp.hpl.jena.sparql.algebra.Op op)
                     throws EmptyRewriteException

Throws:

EmptyRewriteException

rewrite

public SqlNodeOld rewrite(ColRelGenerator generator,
                 com.hp.hpl.jena.sparql.algebra.op.OpExtend op)

rewriteMM

public SqlNodeOld rewriteMM(ColRelGenerator generator,
                   com.hp.hpl.jena.sparql.algebra.Op op)