1. Metadata Tools and Methods Chris Nelson Metanet Conference 2 April 2001

2. Agenda UML CWM OMG/MDA Registries and Repositories

3. Unified Modeling Language - UML The UML is a graphical language created for specifying visualizing constructing documenting the artifacts of software systems. It is based on the object-oriented paradigms (encapsulation,inheritance,polymorphism, instantiation) A large “toolbox”: Use Cases, Different views, Class diagrams, Interaction Diagrams, State Machines, etc.

4. UML Goals Define an easy-to-learn, but semantically rich visual modeling language. Unify the Booch, OMT, and Objectory modeling languages. Include ideas from other modeling languages. Incorporate industry best practices. Address contemporary software development issues –scale, distribution, concurrency, executability, etc. Provide flexibility for applying different processes. Enable model interchange and define repository interfaces (XMI). Communicate knowledge: requester developer.

5. Why (Meta)Model? Understand and describe the problem domain Help others understand the problem domain by using the same language Define a vocabulary for the elements in the problem domain Manage complexity by raising the level of abstraction at which we think and design Civil, Mechanical and hardware engineers have been adept at this for much longer than us Metamodels are used in the domain of modeling middleware and type systems (UML, IDL, CWM…)

6. Role of UML, MOF, XMI Understand, analyze and design software using UML Design and integrate tools, middleware and applications in a flexible manner using MOF –Across previous islands of information Interchange metadata and objects using XML across platforms in a loosely coupled manner (XMI) Interchange metadata and objects using IDL across platforms across languages (MOF2IDL, JMI…) A unifying model driven architecture

7. CWM Why do we need CWM? What is CWM? How can it be used by NSI’s?

8. Data Warehousing/Business Intelligence

9. Metadata management and integration is the number one integration problem in data warehousing and business intelligence: Data warehousing and business intelligence often involve the use of a variety of tools, each with its own definition and format for metadata. Creating, sharing and managing the metadata for these tools is time consuming and error prone.

10. Common Warehouse Metamodel CWM Scope –Data Warehouse lifecycle metadata management Contributors: IBM, Unisys, NCR, Hyperion, Oracle, Genesis, UBS, Dimension EDI... –Metamodel –Generated XML DTDs –Generated MOF - IDL mappings –Generated XML document Adopted by OMG in June 2000 (Oslo) CWM Interoperability showcase in Dec 2000

11. What is CWM? –A Model-based architecture for Data Warehouse interchange. –A common specification that defines, in UML, the structure and semantics of the metadata in data warehousing and business intelligence. –A common specification that defines, in XML, the interchange format and, in IDL, the access API of such shared metadata.

12. The CWM Metamodel Warehouse Process Warehouse Operation Transformation XMLRecord Multi Dimensional Relational Business Information Software Deployment UML 1.3 (Foundation, Behavioral_Elements, Model_Management) Management Resource Analysis Object (UML) Foundation OLAP Data Mining Information Visualization Business Nomenclature Data Types Expressions Keys Index Type Mapping

13. Why UML interchange? –Why not XML DTD or XML Schema? XML DTD –Primitive data model: no inheritance, no operations, no associations, no constraints –Only string data types XML Schema –Same primitive data model as above –Richer data types –UML Rich object-oriented model with associations and constraints Extensible data types: CORBA (MOF), etc.

14. Model Driven Architecture OMG initiative –The Problem We Face: Middleware Proliferation Formalise and standardise models Can be implemented using different technologies –CORBA –XML –EJB

15. MDA and Domains Could have a statistical domain ADM SiG exists and can be used to formalise models Does Metanet want to develop a statistical metamodel –Similar in concept to CWM –Could use CWM as a base

16. Metadata Registries and Repositories Registry stores the metadata about data in a repository Registry objects and associations represent the metadata model The registry object “points” to the data (URL) Central registries can be used for query purposes – e.g. get list of statistical data sets for transport by land between Belgium and Italy for 1993-2000

17. Registry Access Statistical Database NSI A Registry Interface Registry 2 Registry 1 Registry Interface application application (e.g.Servlet) Browser Statistical Database NSI B

18. Registry Standards OASIS –Draft standard submitted by NIST ebXML –Electronic business XML –Based on OASIS model

19. ebXML Registry Model

20. ebXML – Example Registry Method

21. ebXML Registry XML