uk.ac.bbk.dcs.automed.qproc.reformulate
Class LAVInvRulesViewMap

java.lang.Object
  uk.ac.bbk.dcs.automed.qproc.reformulate.CompositeViewMap
      uk.ac.bbk.dcs.automed.qproc.reformulate.LAVInvRulesViewMap

public class LAVInvRulesViewMap
extends CompositeViewMap

Class containing LAV composite views between a single source schema and a single target schema. LAV views are constructed from ADD, EXTEND, RENAME and IDENTITY atomic views. The ADD and EXTEND atomic views need to be processed further before these could be used to form composite views. Currently we used Inverse Rules algorithm as described in the following paper:

           P.J. McBrien and A. Poulovassilis. P2P query reformulation over Both-as-View
           data transformation rules. In Proc of DBISP2P 2006.
 

Author:

Lucas Zamboulis, Sandeep Mittal

Field Summary

Fields inherited from class uk.ac.bbk.dcs.automed.qproc.reformulate.CompositeViewMap

_instanceCache, _logger, _name, _qpc, _sourceSchema, _targetSchema, _viewMap

Constructor Summary

protected

LAVInvRulesViewMap(Schema source, Schema target, QueryProcessorConfiguration qpc) This constructor is called from CompositeViewMap class getInstance() method.

Method Summary

protected void	buildViews() Constructs the composite views
protected boolean	searchAndReplace(Cell c, java.util.Map[] maps, java.util.Set vkSet) LAV view construction may not find all the constructs in target schema for the constructs in the source schema.

Methods inherited from class uk.ac.bbk.dcs.automed.qproc.reformulate.CompositeViewMap

buildViews, composeView, computeName, getFinalConstructs, getInstance, getName, getSourceSchema, getTargetSchema, getViewMap, populateViewMap, showInstanceCache, showViewMap, updateSchemaRef

Methods inherited from class java.lang.Object

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

Constructor Detail

LAVInvRulesViewMap

protected LAVInvRulesViewMap(Schema source,
                             Schema target,
                             QueryProcessorConfiguration qpc)
                      throws BuildViewException

This constructor is called from CompositeViewMap class getInstance() method. Do not otherwise.

Parameters:

source - Source Schema

target - Target Schema

qpc - Query Processor configuration

Throws:

BuildViewException

Method Detail

buildViews

protected void buildViews()
                   throws BuildViewException

Constructs the composite views

Specified by:

buildViews in class CompositeViewMap

Throws:

BuildViewException

searchAndReplace

protected boolean searchAndReplace(Cell c,
                                   java.util.Map[] maps,
                                   java.util.Set vkSet)
                            throws BuildViewException

LAV view construction may not find all the constructs in target schema for the constructs in the source schema. This is a limitation of the LAV query reformulation technique. Hence this method has been overridden to catch such an exception.

Overrides:

searchAndReplace in class CompositeViewMap

Parameters:

c - the root of the IQL query

Throws:

BuildViewException