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Research field Big Data & Model Management
Status completed
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A deductive object manager for meta databases


ConceptBase is a multi-user deductive object manager mainly intended for conceptual modeling and coordination in design environments. The system implements O-Telos, a dialect of Telos which amalgamates properties of deductive and object-oriented languages. Key features are

  • availability on multiple platforms (Windows 2000/XP, Linux i386/x64, Solaris Sun/i386, Mac)
  • logical, frame-like, and graphical network views on the object store
  • unlimited extensibility by meta class hierarchies
  • deductive rules & integrity constraints as attributes of classes
  • queries as classes with membership constraints
  • complex views as extension of query classes
  • user-definable answer formats for queries and views
  • active rules with the ability to database updates and external program calls
  • persistent object store with access to historical states of the database
  • cost-based and semantic query optimization
  • meta-level rules and constraints for axiomatic language extension (improved in V7.0)
  • efficient active rule processor integrated into integrity checker (improved in V7.0)
  • sophisticated graphical editor with user-definable node and link shapes (improved in V7.0)
  • programming interface based on declarative ASK and TELL methods

All classes, meta classes, instances, attributes, rules, constraints, and queries are uniformly represented as objects. Any object may be updated at any time in the life cycle of the object base. Even class membership is regarded as an object and is subject to updates.

The semantics of O-Telos -- esp. class membership, attribution, and inheritance -- is firmly based on rock-solid DATALOG, a simple logic which provides an non-ambiguous way of defining which statements are regarded by the system to be true. Any query posed to the system will terminate and produce the correct answer.

The meta-modeling ability allows to represent heterogeneous modeling languages like entity-relationship diagrams, OMT, etc. as O-Telos meta classes whose rules and constraints encode the axioms of the respective language, e.g. generalization. The meta classes can co-exist within the same object base. Objects described in one modeling language can be explicitely linked to objects described in some other modeling language.

ConceptBase follows a client-server architecture. Client programs can connect to the ConceptBase server and exchange data via the interprocess communication of the Internet protocol. The ConceptBase programming interface allows the users to create their own client programs in pure Java, C or Prolog. The Java-based ConceptBase user interface offers a palette of graphical, tabular, and textual tools for editing and browsing the object base (ERD example, Business Process Modeling example). It runs on any computer that provides a Java runtime enviroment. Embedding of the user interface into a Web page is possible as well.

ConceptBase is currently applied at more than 500 sites world-wide (see references) for research as well as teaching. Being freely distributed since 1990 it is the first and still one of the most widely used DOOD (deductive and object-oriented database) systems world-wide. See here for some information on typical applications of ConceptBase.

Research staff



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Project Publications

Christoph Quix

Model Management

M. Tamer Özsu, Ling Liu (eds.): Encyclopedia of Database Systems. Springer, 2009.

Christoph Quix

Meta Data Repository

M. Tamer Özsu, Ling Liu (eds.): Encyclopedia of Database Systems. Springer, 2009.

Christoph Quix

Metadatabase Design for Data Warehouses

In M.A. Jeusfeld, M. Jarke, J. Mylopoulos (eds.): Metamodeling for Method Engineering, MIT Press 2009, pp. 329-355

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