The evaluation of access costs in object databases

Unfortunately, there is at. present nothing to assist the system architect at design-time to determine whether a proposed architecture based on an obj ect-oriented database system will perform as required. The problem is compl ex, the choice of suitable modelling approach difficult, and a construction of a model is often abstruse. In this paper we concentrate on a major mode l component: that describing the access of objects in a centralised databas e. We present the background for the research (modern corporate IS architec tures), the choices we have made, the prototype design, and the mathematica l model of the cost of object database access. We conclude the paper by des cribing a validation of the model and how it can be generalised. The paper has a number of objectives: first, to dispel the myth that performance mode lling of object-oriented systems is an immensely difficult task; second, to show that techniques which have been in existence for some time for modell ing are applicable, with some modification, to aspects of object-oriented d atabase performance prediction; and, third, to detail a specific case study of access cost modelling which provides enough information to be replicate d by other workers across a number of object-oriented database products. (C ) 2000 Elsevier Science B.V. All rights reserved.