Plug and Play with Query Algebras: SECONDO
A Generic DBMS Development Environment

Stefan Dieker and Ralf Hartmut Güting

Praktische Informatik IV, FernUniversität Hagen
D-58084 Hagen
{stefan.dieker,gueting}@fernuni-hagen.de

Abstract: We present SECONDO, a new generic environment supporting the implementation of database systems for a wide range of data models and query languages. On the one hand, this framework is more flexible than common extensible and object-relational systems, offering the full extensibility of second-order signature, the formal basis for data and query language definitions in SECONDO. On the other hand, it is much more complete and structured than database system toolkits. Extensibility is provided by the concept of algebra modules defining and implementing new types (type constructors, in fact) and operators. Support functions are used to register them with the system frame.

After a review of second-order signature essentials, this paper presents the system functionality, given by a uniform set of user commands valid for all data models, and the extensible system architecture. All common DBMS features are implemented in the system frame; only purely data model dependent functionality is coded in algebra modules, supported by a variety of tools. Furthermore, we describe the key strategies for extensible query processing in the SECONDO environment and explain the structure of algebra modules.

Keywords: Extensible database systems, extensible system architectures, algebra modules, extensible query processing, algebraic specifications

Published: FernUniversität Hagen, Informatik-Report 249, February 1999