Our work on  schema and metadata management focuses on the following areas:

• Schema and Ontology Matching: finding semantic correspondences between schema elements (Match operator).
• Evolution of Ontologies and Mappings.
• Model Management: a powerful approach to generic metadata management that manipulates  models and mappings between models using high-level operators.
• Further metadata issues, e.g., in data warehouses.

We implement our approaches in prototypes such as COMA++, and Rondo.

Model Management

Generic metadata management aims at simplifying the development of metadata-intensive applications, such as data integration, software engineering, website management, or network modeling applications. Such applications manipulate a variety of 

• models (database schemas, XML schemas, UML / ER)diagrams, ontologies, etc.) and
• mappings between models (SQL view definitions, XSLT transformations,   XML-to-relational shredding specifications, ER-to-SQL DDL mappings, etc.).  

Model Management is a powerful approach to generic metadata management not limited to a specific language or application domain.  Models and mappings are manipulated using high-level algebraic operators, such as Match, Merge, or Compose. These operators are applied to models and mappings as a whole rather than to their individual building blocks. This approach, which was proposed by Phil Bernstein et al., promises to make the programming of metadata-intensive applications substantially easier.

Some of our key contributions are:

• Study of scenarios related to data warehousing to demonstrate the usefulness of model management (ER 2000)
• Development of the first prototype implementation of a complete programming environment for model- management, called Rondo, and its use to solve several realistic metadata problems (SIGMOD 2003). An executable demo of Rondo is available for download. 

Specific metadata issues

We also studied metadata management for data warehouses, in particular integrated support for business and technical metadata (DMDW 99, TR 2000).

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Project members

• Prof. Dr. Erhard Rahm
• Hong Hai Do
• Sergey Melnik

Publications ————

Kirsten, T.; Thor, A.; Rahm, E. Instance-based matching of large life science ontologies Proc. DILS 2007, LNCS 2007-06 [13 citations]

Do, H.-H.; Rahm, E. Matching Large Schemas: Approaches and Evaluation Information Systems, Volume 32, Issue 6, September 2007, Pages 857-885 2007 [65 citations]

Do, Hai Hong Schema Matching and Mapping-based Data Integration Dissertation. Veröffentlich durch Verlag Dr. Müller (VDM), ISBN 3-86550-997-5, 2006

Rahm, Erhard; Bernstein, Philip A. An Online Bibliography on Schema Evolution Sigmod Record, Dec. 2006 2006 [22 citations]

Aumueller, D.; Do, H.H.; Massmann, S.; Rahm, E. Schema and ontology matching with COMA++ SIGMOD Conference 2005-06 [205 citations]

Melnik, S.; Bernstein P.A.; Halevy, A.; Rahm, E. Supporting Executable Mappings in Model Management Proc. SIGMOD 2005, Baltimore, June 2005 2005-06 [60 citations]

Melnik, S. Generic Model Management: Concepts and Algorithms Springer LNCS 2967 2004 [72 citations]

Do, H.H.; Melnik, S.; Rahm, E. Comparison of Schema Matching Evaluations Proc. Workshop Web and Databases, LNCS 2593, 2003 2003 [254 citations]

Melnik, S.; Rahm, E.; Bernstein, P.A. Rondo: A Programming Platform for Generic Model Management, Proc. ACM SIGMOD 2003 2003 [232 citations]

Melnik, S.; Rahm, E.; Bernstein, P.A. Developing Metadata-Intensive Applications with Rondo. Journal on Web Semantics, 2003 2003 [27 citations]

Do, H.H.; Melnik, S.; Rahm, E. Comparison of Schema Matching Evaluations. Proc. GI-Workshop “Web and Databases”, Erfurt, Oct. 2002 2002 [254 citations]

Do, H.H.; Rahm, E. COMA - A System for Flexible Combination of Schema Matching Approaches Proc. 28th Intl. Conference on Very Large Databases (VLDB), Hongkong, Aug. 2002 2002 [589 citations]

Melnik, S. Generic Model Management: Experience and Open Questions. Doctoral Poster, VLDB conf. 2002, Hongkong, Aug. 2002 2002

Melnik, S.; Garcia-Molina, H.; Rahm, E. Similarity Flooding: A Versatile Graph Matching Algorithm and its Application to Schema Matching Proc. 18th International Conference on Data Engineering (ICDE), San Jose, 2002 2002 [712 citations]

Madhavan, J.; Bernstein, P.A.; Rahm, E. Generic schema matching with Cupid. Proc. 27th Intl. Conference on Very Large Databases (VLDB), Rome, Italy, Sep. 2001 2001 [1040 citations]

Rahm, E.; Bernstein, P.A. A Survey of Approaches to Automatic Schema Matching VLDB Journal 10 (4) 2001 [1938 citations]

Rahm, E.; Bernstein, P.A. On Matching Schemas Automatically Techn. Report 1/2001. Dept. of Comp. Science, Univ. of Leipzig, Feb. 2001 2001 [159 citations]

Bernstein, P.A.; Rahm, E. Data Warehouse Scenarios for Model Management Proc. 19th Int. Conf. on Entity-Relationship Modelling, Oct. 2000, LNCS, Springer 2000 [104 citations]

Rahm, E.; Do, H.H. Data Cleaning: Problems and Current Approaches IEEE Techn. Bulletin on Data Engineering, Dec. 2000 2000 [421 citations]

Müller, R.; Stöhr, T.; Rahm, E. An Integrative and Uniform Model for Metadata Management in Data Warehousing Environments. Proceedings Workshop on Design and Management of Data Warehouses (DMDW’99), Heidelberg, June 1999 1999 [39 citations]

Related Panel

Bernstein, P.A., Is Generic Data Management Feasible? Panel discussion, Proc. VLDB 2000, pp. 660-662