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

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

public class NewGAVQueryReformulationProvider
extends java.lang.Object

The query reformulator accepts an IQL query on the source schema and rewrites it in terms of constructs of the target schemata.

To do this, on construction, the query reformulator traverses the pathways from the source schema to the target schemata and builds a view definition over target schema constructs for each source schema construct.

Field Summary

private QueryProcessorConfiguration	_qpc
protected java.util.logging.Logger	logger
protected Schema	sourceSchema
protected Schema[]	targetSchemata
protected java.util.Map	viewmap Viewmap contains the constructs of the source schema in the LHS and the IQL view of each construct of the LHS in the RHS.
private static java.util.Map	viewmap_cache

Constructor Summary

protected	NewGAVQueryReformulationProvider()
	NewGAVQueryReformulationProvider(Schema sourceSchema, Schema[] targetSchemata, QueryProcessorConfiguration qpc)

Method Summary

private void	branch(Cell n, Schema fromSchema, java.lang.Object[] tos) Updates the view definitions (viewmap).
protected void	buildViews() Traverses BAV pathways and builds GAV views.
private void	changeSchemaRef(Cell n, Schema fromSchema, Schema to) Updates the view definition hashmap when the 'from' schema has only one 'to' schema.
private void	checkFinalConstructs()
void	finalize()
static void	main(java.lang.String[] args)
private static void	o(java.lang.Object s)
private void	populateViewMapLHS(Schema sourceSchema) Populates the LHS of the viewmap with schemes from source schema
private void	processTransformation(Schema fromSchema, Schema toSchema)
void	reformulate(ASG g, QueryProcessorConfiguration qpc) Reformulates the query represented by the ASG g according to the view defintions it has stored.
private void	replace(SchemeInfo si, Cell q, Cell root)
private void	replaceNullSchemaRefs(Cell r, java.lang.String sName)
private void	showViewMap()
private void	unifyViewDefinitions() Performs variable unification on each view definition in the viewmap.
private void	updateSchemeInfo(Cell c)
private void	updateSchemeInfoInViewMap() Method goes through all view definitions and updates SchemeInfo objects with Model, ConstructType and Type information (if present in the repository).

Methods inherited from class java.lang.Object

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

Field Detail

logger

protected java.util.logging.Logger logger

sourceSchema

protected Schema sourceSchema

targetSchemata

protected Schema[] targetSchemata

viewmap

protected java.util.Map viewmap

Viewmap contains the constructs of the source schema in the LHS and the IQL view of each construct of the LHS in the RHS.

_qpc

private QueryProcessorConfiguration _qpc

viewmap_cache

private static java.util.Map viewmap_cache

Constructor Detail

NewGAVQueryReformulationProvider

protected NewGAVQueryReformulationProvider()

NewGAVQueryReformulationProvider

public NewGAVQueryReformulationProvider(Schema sourceSchema,
                                        Schema[] targetSchemata,
                                        QueryProcessorConfiguration qpc)
                                 throws QueryReformulationException

Parameters:

sourceschema - the source schema

targetschemata - the target schemata

qpc - the input configuration

Throws:

QueryReformulationException - if there was a problem building the view definitions of the source schema constructs over target schema constructs

Method Detail

buildViews

protected void buildViews()
                   throws QueryReformulationException

Traverses BAV pathways and builds GAV views.

Throws:

QueryReformulationException

IntegrityException

NotFoundException

showViewMap

private void showViewMap()

populateViewMapLHS

private void populateViewMapLHS(Schema sourceSchema)

Populates the LHS of the viewmap with schemes from source schema

Parameters:

sourceSchema - the source schema

unifyViewDefinitions

private void unifyViewDefinitions()
                           throws QueryReformulationException

Performs variable unification on each view definition in the viewmap.

Throws:

QueryReformulationException

QueryReformulationException

updateSchemeInfoInViewMap

private void updateSchemeInfoInViewMap()
                                throws NotFoundException

Method goes through all view definitions and updates SchemeInfo objects with Model, ConstructType and Type information (if present in the repository).

Throws:

NotFoundException

updateSchemeInfo

private void updateSchemeInfo(Cell c)
                       throws NotFoundException

Throws:

NotFoundException

processTransformation

private void processTransformation(Schema fromSchema,
                                   Schema toSchema)
                            throws NotFoundException,
                                   QueryReformulationException

Throws:

NotFoundException

QueryReformulationException

replaceNullSchemaRefs

private void replaceNullSchemaRefs(Cell r,
                                   java.lang.String sName)

replace

private void replace(SchemeInfo si,
                     Cell q,
                     Cell root)

changeSchemaRef

private void changeSchemaRef(Cell n,
                             Schema fromSchema,
                             Schema to)
                      throws NotFoundException

Updates the view definition hashmap when the 'from' schema has only one 'to' schema. The only thing it updates is the schema reference of SchemeInfo objects found in the view definitions.

Parameters:

n - the view to be updated

fromSchema - the 'from' schema

to - the 'to' schema

Throws:

NotFoundException

branch

private void branch(Cell n,
                    Schema fromSchema,
                    java.lang.Object[] tos)
             throws NotFoundException,
                    QueryReformulationException

Updates the view definitions (viewmap). Building viewmap occurs by a breadth-first traversal, so at each depth, and for each pathway, if a 'from' schema has more than one 'to' schemas, the viewmap is updated using this method.

Parameters:

n - the view definition to be updated

fromSchema - the schema where the branching occurs

tos - the schemas resulting from the branching

Throws:

NotFoundException

QueryReformulationException

reformulate

public void reformulate(ASG g,
                        QueryProcessorConfiguration qpc)
                 throws QueryReformulationException

Reformulates the query represented by the ASG g according to the view defintions it has stored.

Throws:

QueryReformulationException

finalize

public void finalize()

Overrides:

finalize in class java.lang.Object

checkFinalConstructs

private void checkFinalConstructs()

o

private static void o(java.lang.Object s)

main

public static void main(java.lang.String[] args)
                 throws java.lang.Exception

Throws:

java.lang.Exception