Towards a Flexible and Transparent Database Evolution

Abstract

Abstract. Applications refactorings that imply the schema evolution are common activities in programming practices. Although modern objectoriented databases provide transparent schema evolution mechanisms, those refactorings continue to be time consuming tasks for programmers. In this paper we address this problem with a novel approach based on aspect-oriented programming and orthogonal persistence paradigms, as well as our meta-model. An overview of our framework is presented. This framework, a prototype based on that approach, provides applications with aspects of persistence and database evolution. It also provides a new pointcut/advice language that enables the modularization of the instance adaptation crosscutting concern of classes, which were subject to a schema evolution. We also present an application that relies on our framework. This application was developed without any concern regarding persistence and database evolution. However, its data is recovered in each execution, as well as objects, in previous schema versions, remain available, transparently, by means of our framework.

Modularizing application and database evolution - an aspect-oriented framework for orthogonal persistence

“…Although performance degradation was not perceptible in our tests, it exists because of the additional mechanisms of versioning implemented. However, in our geographical application , because of the use of large arrays of objects, this performance degradation was observable.…”

“…In terms of database evolution support, our framework offers more transparent mechanisms which affect positively the programmers' productivity. Our framework avoids the need for helper programs in many scenarios, like the one discussed in this paper (as well as a geographical application presented in ). The development of such helper programs penalizes the workload in terms of productivity, because they are additional tasks for the programmers.…”

“…Our framework mediates the interaction between applications and the OODBS, following an aspect‐oriented approach. In the next section, we will discuss the programming environment of our prototype, the aspect‐oriented framework for object orthogonal persistence (AOF4OOP) framework.…”

“…These expressions are structured into two parts: trigger conditions and action. In Table , we present a quick reference guide for these constructs, improved because our last publication .…”

“…This paper goes beyond the previous publications by giving an updated view of our framework and by discussing implementation details that were never published before.…”