uk.ac.bbk.dcs.automed.evolution.schemaEvolution
Class SchemaEvolution

java.lang.Object
  uk.ac.bbk.dcs.automed.evolution.schemaEvolution.SchemaEvolution

All Implemented Interfaces:

EvolutionInterface

Direct Known Subclasses:

DataSourceSchemaEvolution, DerivedSchemaEvolution

public class SchemaEvolution
extends java.lang.Object
implements EvolutionInterface

Main class of the schema evolution package. Works by creating a new pathway, and then deletes the old pathway, if user wishes so. Cannot repair the pathway. For further information on schema evolution in AutoMed, see

• H. Fan and A. Poulovassillis, Schema Evolution in a Data Warehousing Environments - a schema-transformation based approach, in Proc. of ER'04, Springer Verlag LNCS 3288, Pages 639-653, 2004.
• P.J. McBrien and A. Poulovassilis, Schema Evolution in Heterogeneous Database Architectures, A Schema Transformation Approach, in Proc. of CAiSE02, Springer Verlag LNCS, Volume 2348, Pages 484-499, 2002

Author:

Lucas Zamboulis, Dheeraj Mudgil

Field Summary

protected Schema[]	dataSourceSchemas The schemas that have the role of the data source schemas in the evolution setting
protected Schema	derivedSchema The schema that has the role of the derived schema in the evolution setting
static int	EVOLUTION_TYPE_SCHEMA_AND_DATA Evolution is both schema and data
static int	EVOLUTION_TYPE_SCHEMA_ONLY Evolution is only schema, not data
protected Transformation[]	evolutionPathway The pathways from the data source schemas to the derived schema
protected int	evolutionType
static int	EVOLVED_SCHEMA_TYPE_DATASOURCE Constant representing evolution of local (extensional) schema
static int	EVOLVED_SCHEMA_TYPE_DERIVED Constant representing evolution of virtual (integrated) schema
protected int	evolvedSchemaType
protected static java.util.logging.Logger	logger
protected Transformation[][]	pathwaysToUnionSchemas The pathways from the data source schemas to the union schemas
protected Transformation[]	pathwayToDerivedSchema The pathway from one of the union schemas to the derived schema
protected Schema[]	unionSchemas The schemas that have the role of the union schemas in the evolution setting

Constructor Summary

protected

SchemaEvolution()

Method Summary

Schema[]	getDataSourceSchemas()
Schema	getDerivedSchema()
Transformation[]	getEvolutionPathway()
int	getEvolutionType()
int	getEvolvedSchemaType()
Transformation[][]	getPathwaysToUnionSchemas()
Transformation[]	getPathwayToDerivedSchema()
protected void	processAddTransformation(Transformation t) Processes an add transformation
protected void	processContractTransformation(Transformation t) Processes a contract transformation
static Schema	processDataSourceSchemaEvolution(int evolutionType, Schema derivedSchema, Schema[] unionSchemas, Transformation[][] pathwaysToUnionSchemas, Transformation[] evolutionPathway, java.util.Map domainKnowledge, boolean removeDescendants, boolean removeOldPathway) Processes the evolution pathway of the data source schema.
protected void	processDeleteTransformation(Transformation t) Processes a delete transformation
static void	processDerivedSchemaEvolution(int evolutionType, Schema derivedSchema, Schema[] unionSchemas, Transformation[][] pathwaysToUnionSchemas, Transformation[] evolutionPathway) Processes the evolution pathway of the derived schema.
protected void	processEvolution() Processes the evolution pathway one transformation at a time.
protected void	processExtendTransformation(Transformation t) Processes an extend transformation
protected void	processIdentTransformation(Transformation t) Processes an ident transformation
protected void	processNewPathways(Schema newDerivedSchema)
protected void	processRenameTransformation(Transformation t) Processes a rename transformation
protected void	setPathwayToDerivedSchema()

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

derivedSchema

protected Schema derivedSchema

The schema that has the role of the derived schema in the evolution setting

unionSchemas

protected Schema[] unionSchemas

The schemas that have the role of the union schemas in the evolution setting

dataSourceSchemas

protected Schema[] dataSourceSchemas

The schemas that have the role of the data source schemas in the evolution setting

pathwaysToUnionSchemas

protected Transformation[][] pathwaysToUnionSchemas

The pathways from the data source schemas to the union schemas

pathwayToDerivedSchema

protected Transformation[] pathwayToDerivedSchema

The pathway from one of the union schemas to the derived schema

evolutionPathway

protected Transformation[] evolutionPathway

The pathways from the data source schemas to the derived schema

EVOLUTION_TYPE_SCHEMA_ONLY

public static final int EVOLUTION_TYPE_SCHEMA_ONLY

Evolution is only schema, not data

See Also:

Constant Field Values

EVOLUTION_TYPE_SCHEMA_AND_DATA

public static final int EVOLUTION_TYPE_SCHEMA_AND_DATA

Evolution is both schema and data

See Also:

Constant Field Values

evolutionType

protected int evolutionType

EVOLVED_SCHEMA_TYPE_DERIVED

public static final int EVOLVED_SCHEMA_TYPE_DERIVED

Constant representing evolution of virtual (integrated) schema

See Also:

Constant Field Values

EVOLVED_SCHEMA_TYPE_DATASOURCE

public static final int EVOLVED_SCHEMA_TYPE_DATASOURCE

Constant representing evolution of local (extensional) schema

See Also:

Constant Field Values

evolvedSchemaType

protected int evolvedSchemaType

Constructor Detail

SchemaEvolution

protected SchemaEvolution()

Method Detail

processDerivedSchemaEvolution

public static final void processDerivedSchemaEvolution(int evolutionType,
                                                       Schema derivedSchema,
                                                       Schema[] unionSchemas,
                                                       Transformation[][] pathwaysToUnionSchemas,
                                                       Transformation[] evolutionPathway)
                                                throws EvolutionException

Processes the evolution pathway of the derived schema.

Parameters:

evolutionType - schema or schema and data evolution

derivedSchema - the derived schema in this evolution setting

unionSchemas - the union schemas of the integration setting

pathwaysToUnionSchemas - the pathways from the data source schemas of this evolution setting to the union schemas of this evolution setting

evolutionPathway - the pathway from the original data source or derived schema to the evolved data source or derived schema

Throws:

EvolutionException - an exception thrown while handling the evolution of a schema

processDataSourceSchemaEvolution

public static final Schema processDataSourceSchemaEvolution(int evolutionType,
                                                            Schema derivedSchema,
                                                            Schema[] unionSchemas,
                                                            Transformation[][] pathwaysToUnionSchemas,
                                                            Transformation[] evolutionPathway,
                                                            java.util.Map domainKnowledge,
                                                            boolean removeDescendants,
                                                            boolean removeOldPathway)
                                                     throws EvolutionException

Processes the evolution pathway of the data source schema.

Parameters:

evolutionType - schema or schema and data evolution

derivedSchema - the derived schema in this evolution setting

unionSchemas - the union schemas of the integration setting

pathwaysToUnionSchemas - the pathways from the data source schemas of this evolution setting to the union schemas of this evolution setting

evolutionPathway - the pathway from the original data source or derived schema to the evolved data source or derived schema

domainKnowledge - domain expert input regarding the semantics of constructs related to the evolution of the data source schema

removeDescendants - if true, Range Void Any descendants are to be removed from union and/or derived schema

removeOldPathway - if true, old pathway is to be removed

newName - if one or more new derived schemas are created during the evolution processing, newName is the name to be given to the final derived schema

Throws:

EvolutionException - an exception thrown while handling the evolution of a schema

processNewPathways

protected void processNewPathways(Schema newDerivedSchema)
                           throws EvolutionException

Throws:

EvolutionException

processEvolution

protected final void processEvolution()
                               throws EvolutionException

Processes the evolution pathway one transformation at a time.

Parameters:

oldTs[] - the evolution pathway (of the data source or the derived schema)

Throws:

EvolutionException

processAddTransformation

protected void processAddTransformation(Transformation t)
                                 throws EvolutionException

Processes an add transformation

Parameters:

t - transformation to process

Throws:

EvolutionException

processDeleteTransformation

protected void processDeleteTransformation(Transformation t)
                                    throws EvolutionException

Processes a delete transformation

Parameters:

t - transformation to process

Throws:

EvolutionException

processExtendTransformation

protected void processExtendTransformation(Transformation t)
                                    throws EvolutionException

Processes an extend transformation

Parameters:

t - transformation to process

Throws:

EvolutionException

processContractTransformation

protected void processContractTransformation(Transformation t)
                                      throws EvolutionException

Processes a contract transformation

Parameters:

t - transformation to process

Throws:

EvolutionException

processRenameTransformation

protected void processRenameTransformation(Transformation t)

Processes a rename transformation

Parameters:

t - transformation to process

Throws:

EvolutionException

processIdentTransformation

protected void processIdentTransformation(Transformation t)

Processes an ident transformation

Parameters:

t - transformation to process

getDerivedSchema

public final Schema getDerivedSchema()

Specified by:

getDerivedSchema in interface EvolutionInterface

Returns:

the schema that has the role of the derived schema in the evolution setting

getDataSourceSchemas

public final Schema[] getDataSourceSchemas()

Specified by:

getDataSourceSchemas in interface EvolutionInterface

Returns:

the schemas that have the role of the data source schemas in the evolution setting

getPathwaysToUnionSchemas

public final Transformation[][] getPathwaysToUnionSchemas()

Specified by:

getPathwaysToUnionSchemas in interface EvolutionInterface

Returns:

the pathways from the data source schemas to the union schemas

getPathwayToDerivedSchema

public final Transformation[] getPathwayToDerivedSchema()

Specified by:

getPathwayToDerivedSchema in interface EvolutionInterface

Returns:

the transformations in the pathway from one of the union schemas to the derived schema

getEvolutionPathway

public final Transformation[] getEvolutionPathway()

Specified by:

getEvolutionPathway in interface EvolutionInterface

Returns:

the evolution pathway (of the data source schema or of the derived schema)

getEvolutionType

public int getEvolutionType()

Specified by:

getEvolutionType in interface EvolutionInterface

Returns:

one of EVOLUTION_TYPE_SCHEMA_ONLY,EVOLUTION_TYPE_SCHEMA_AND_DATA

getEvolvedSchemaType

public int getEvolvedSchemaType()

Specified by:

getEvolvedSchemaType in interface EvolutionInterface

Returns:

one of EVOLVED_SCHEMA_TYPE_DERIVED,EVOLVED_SCHEMA_TYPE_DATASOURCE

setPathwayToDerivedSchema

protected void setPathwayToDerivedSchema()
                                  throws EvolutionException

Throws:

EvolutionException