it.unibz.inf.ontop.iq.optimizer.impl

Class NodeCentricDepthFirstOptimizer<P extends SimpleNodeCentricOptimizationProposal<? extends QueryNode>>

java.lang.Object

it.unibz.inf.ontop.iq.optimizer.impl.NodeCentricDepthFirstOptimizer<P>

All Implemented Interfaces:

IntermediateQueryOptimizer

Direct Known Subclasses:

BasicJoinMutableOptimizer, BasicLeftJoinMutableOptimizer

public abstract class NodeCentricDepthFirstOptimizer<P extends SimpleNodeCentricOptimizationProposal<? extends QueryNode>>
extends Object
implements IntermediateQueryOptimizer

Optimizer that evaluates the QueryNode-s one by one in a Depth-First order. When evaluating one QueryNode, it can make one proposal.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	NodeCentricDepthFirstOptimizer(boolean canEmptyQuery)

Method Summary

Modifier and Type	Method and Description
protected abstract Optional<P>	evaluateNode(QueryNode node, IntermediateQuery query)
IntermediateQuery	optimize(IntermediateQuery query) TODO: explain
protected IntermediateQuery	optimizeQuery(IntermediateQuery initialQuery)

Methods inherited from class java.lang.Object

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

Constructor Detail

NodeCentricDepthFirstOptimizer

protected NodeCentricDepthFirstOptimizer(boolean canEmptyQuery)

Method Detail

optimize

public IntermediateQuery optimize(IntermediateQuery query)
                           throws EmptyQueryException

Description copied from interface: IntermediateQueryOptimizer

TODO: explain

Specified by:

optimize in interface IntermediateQueryOptimizer

Throws:

EmptyQueryException

optimizeQuery

protected IntermediateQuery optimizeQuery(IntermediateQuery initialQuery)
                                   throws EmptyQueryException

Throws:

EmptyQueryException

evaluateNode

protected abstract Optional<P> evaluateNode(QueryNode node,
                                            IntermediateQuery query)