LIBD:Themes:SPECIAL-Active-Databases

Version du 4 décembre 2010 à 23:31

Special Databases

Active Databases

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• Description

An active (or reactive) database is able to react to some external stimuli, such as data modification actions. Practically, the reaction mechanism relies on triggers, predicates and SQL procedures. A specific reaction can be defined through different patterns. The first one is the predicate (SQL check), which states a static property that the data must always meet. Any action that will violate this property is rejected. The second one specifies a procedure that must be executed before or after definite data modification actions (SQL trigger). The third one consists of a procedure of arbitrary complexity (SQL stored procedure) that can be called by users, by client programs or by triggers.

A short introduction to active database can be found in book [B09], chapter 9 and appendix C. A simple design methodology and a practical application are developed in technical reports [TR01-01], [TR01-02] and [TR01-03]. Building an active database that manages complex is-a hierarchies in SQL2 is described in [TR03-02]. Reference [P90-02] describes a decision support model coupling a database with a computing model. This application is described in more detail in the theme Databases and Computing Models, which shows that such a model can be implemented as an active database.

Temporal databases are an important application of active databases [B02-01]. See the theme Special Databases > Temporal Databases for more detail.

• Keywords

active database, Is-a relation management, active rule, SQL trigger, SQL predicate, SQL stored procedure, integrity management, update propagation, decision support system, temporal database

• Resources

[B09] Jean-Luc Hainaut. Bases de données - Concepts, utilisation et développement, Dunod, Collection Sciences Sup, Paris, 2009. [book description]

[B02-01] Jean-Luc Hainaut, Virginie Detienne. Introduction pratique aux bases de données temporelles novembre 2002, 116 pages. [full text]

[P90-02] Jean-Luc Hainaut. Systèmes d’aide à la décision : une approche méthodologique intégrée, in Actes du congrès INFORSID 1990, pages 7-34, Eyrolles-Afcet, 1990. [description] [full text]

[B02-01]

[TR03-02] Anne-France Brogneaux, Jean-Luc Hainaut. Une approche complète de représentation des relations ISA en SQL2, rapport final du projet Active Database, mars 2003, 19 pages, [full text]

[TR01-03] Anne-France Brogneaux, Jean-Luc Hainaut. Générateur SQL paramétrique, rapport final du projet Active Database, février 2001, 57 pages, [full text]

[TR01-02] Anne-France Brogneaux, Jean-Luc Hainaut. Validation de règles actives - Etat de l’art et prototypes d’outils, rapport final du projet Active Database, février 2001, 36 pages, [full text]

[TR01-01] Anne-France Brogneaux, Jean-Luc Hainaut. Bases de données actives et règles de comportement - Eléments méthodologiques et étude de cas, rapport final du projet Active Database, février 2001, 152 pages, [full text]

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