Package se.liu.ida.hefquin.engine.queryproc.impl.loptimizer.heuristics

Class RemoveUnnecessaryL2gAndG2l

java.lang.Object

se.liu.ida.hefquin.engine.queryproc.impl.loptimizer.heuristics.RemoveUnnecessaryL2gAndG2l

All Implemented Interfaces:

HeuristicForLogicalOptimization

public class RemoveUnnecessaryL2gAndG2l
extends Object
implements HeuristicForLogicalOptimization

Constructor Summary

Constructors

Constructor	Description
RemoveUnnecessaryL2gAndG2l()

Method Summary

Modifier and Type	Method	Description
LogicalPlan	apply(LogicalPlan inputPlan)	Applies this heuristics to the given plan and returns the resulting, potentially rewritten plan.
protected boolean	checkIfL2gOrG2lNeeded(LogicalPlan plan)	This function is used to check if a l2g or g2l operator is needed.
protected static Set<TriplePattern>	extractTPs(LogicalPlan plan)

Methods inherited from class java.lang.Object

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

Constructor Details

RemoveUnnecessaryL2gAndG2l

public RemoveUnnecessaryL2gAndG2l()

Method Details

apply

public LogicalPlan apply(LogicalPlan inputPlan)

Description copied from interface: HeuristicForLogicalOptimization

Applies this heuristics to the given plan and returns the resulting, potentially rewritten plan.

Specified by:

apply in interface HeuristicForLogicalOptimization

checkIfL2gOrG2lNeeded

protected boolean checkIfL2gOrG2lNeeded(LogicalPlan plan)

This function is used to check if a l2g or g2l operator is needed. The current implementation assumes that only concepts and roles are being considered in vocabulary mapping and that the data of the federation members is only instance data (i.e., properties appear only in the predicate position of triples and classes appear only in the object position of rdf:type triples).

extractTPs

protected static Set<TriplePattern> extractTPs(LogicalPlan plan)