Marc Wenger (Centre de donnees astronomiques de Strasourgb), Fabrice Kinnar (Haute ecole de la province de Liege Renn), Rudi Jocqueau (Haute ecole de la province de Liege Renn)
Simbad is an astronomical database organized around astronomical objects. Simbad gathers very heterogeneous information, both in type and size, about astronomical objects, which makes it particularly suitable for Object Oriented Database Management Systems (ODBMS). And, as a matter of fact, the Simbad software was already build in-house around object oriented concepts more than 10 years ago.
It was therefore tempting to build a prototype of Simbad using now available commercial ODMBS. Two prototypes were build independently with Objectivity/DB and O2 (ArdentSoftware), allowing us to explore these two database systems and compare their functionalities and performances.
The paper presents the results of this work. It shows how the database design has to fit with the existing functionalities provided by each system, how data loading has to be organized differently in each system according to performance problems. Queries using the current Simbad and the two prototypes are compared.
More generally, the type of application suitable for each Database system is discussed.