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

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

Direct Known Subclasses:

BAVViewMap, GAVViewMap, LAVInvRulesViewMap

public abstract class CompositeViewMap
extends java.lang.Object

Class containing common functionality for creating composite views from atomic views. Composite views are constructed from ADD, EXTEND, DELETE, CONTRACT, RENAME and IDENTITY atomic views. For LAV and BAV techniques, 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

protected static java.util.Map	_instanceCache
protected static java.util.logging.Logger	_logger
protected java.lang.String	_name
protected QueryProcessorConfiguration	_qpc
protected Schema	_sourceSchema
protected Schema	_targetSchema
protected java.util.Map	_viewMap

Constructor Summary

protected

CompositeViewMap(Schema source, Schema target, QueryProcessorConfiguration qpc) Constructs a new CompositeViewMap object for the input source and target schemas, then populates it.

Method Summary

protected abstract void	buildViews()
protected void	buildViews(java.util.Map[] maps)
protected Cell	composeView(java.util.Map[] maps, ViewKey vk)
static java.lang.String	computeName(Schema source, Schema target, QueryProcessorConfiguration qpc)
protected java.util.Set	getFinalConstructs()
static CompositeViewMap	getInstance(Schema source, Schema target, QueryProcessorConfiguration qpc)
java.lang.String	getName()
Schema	getSourceSchema()
Schema	getTargetSchema()
java.util.Map	getViewMap()
protected void	populateViewMap(Schema schema) Populates the LHS of the viewmap with schemes from source schema.
protected boolean	searchAndReplace(Cell c, java.util.Map[] maps, java.util.Set vkSet) Goes through an IQL query and replaces each scheme encountered with its view definition found in the AtomicViewMaps
static void	showInstanceCache()
protected void	showViewMap()
protected void	updateSchemaRef(Cell n, Schema aSchema) Forces the schema reference for a Cell tree to the given schema.

Methods inherited from class java.lang.Object

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

Field Detail

_logger

protected static java.util.logging.Logger _logger

_sourceSchema

protected Schema _sourceSchema

_targetSchema

protected Schema _targetSchema

_name

protected java.lang.String _name

_viewMap

protected java.util.Map _viewMap

_instanceCache

protected static java.util.Map _instanceCache

_qpc

protected QueryProcessorConfiguration _qpc

Constructor Detail

CompositeViewMap

protected CompositeViewMap(Schema source,
                           Schema target,
                           QueryProcessorConfiguration qpc)

Constructs a new CompositeViewMap object for the input source and target schemas, then populates it.

Parameters:

source - the input source schema

target - the input target schema

qpc - Query processor configuration

Throws:

BuildViewException - if a problem is encountered during the population of the map

Method Detail

getInstance

public static CompositeViewMap getInstance(Schema source,
                                           Schema target,
                                           QueryProcessorConfiguration qpc)
                                    throws BuildViewException

Parameters:

source - source schema

target - target schema

qpc - Query processor configuration

Returns:

the CompositeViewMap specified by the input parameters - if one exists in the internal cache, a reference to it is returned, otherwise a new CompositeViewMap is created based on the input parameters

Throws:

BuildViewException

computeName

public static java.lang.String computeName(Schema source,
                                           Schema target,
                                           QueryProcessorConfiguration qpc)

getViewMap

public java.util.Map getViewMap()

getTargetSchema

public Schema getTargetSchema()

getSourceSchema

public Schema getSourceSchema()

getName

public java.lang.String getName()

buildViews

protected abstract void buildViews()
                            throws BuildViewException

Throws:

BuildViewException

buildViews

protected void buildViews(java.util.Map[] maps)
                   throws BuildViewException

Throws:

BuildViewException

getFinalConstructs

protected java.util.Set getFinalConstructs()

searchAndReplace

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

Goes through an IQL query and replaces each scheme encountered with its view definition found in the AtomicViewMaps

Parameters:

c - the root of the IQL query

Throws:

BuildViewException

composeView

protected Cell composeView(java.util.Map[] maps,
                           ViewKey vk)
                    throws NotFoundException

Throws:

NotFoundException

populateViewMap

protected void populateViewMap(Schema schema)

Populates the LHS of the viewmap with schemes from source schema. Note that the viewmap contains two versions of each scheme (shorthand + verbose).

Parameters:

schema - the source schema

updateSchemaRef

protected void updateSchemaRef(Cell n,
                               Schema aSchema)

Forces the schema reference for a Cell tree to the given schema.

Parameters:

n - Root cell of a comprehension or Cell tree.

aSchema - New schema reference.

showViewMap

protected void showViewMap()

showInstanceCache

public static void showInstanceCache()