On the Use of a Reflective Architecture to Augment Database Management Systems

Abstract: the database management system (dbms) used to be a commodity soft- ware component, with well known standard interfaces and semantics. however, the performance and reliability expectations being placed on dbmss have increased the demand for a variety add-ons, that augment the functionality of the database in a wide range of deployment scenarios, offering support for features such as clustering, replica- tion, and self-management, among others. a well known software engineering approach to systems with such requirements is reflection. unfortunately, standard reflective in- terfaces in dbmss are very limited. some of these limitations may be circumvented by implementing reflective features as a wrapper to the dbms server. unfortunately, these solutions comes at the expense of a large development effort and significant per- formance penalty. in this paper we propose a general purpose dbms reflection architecture and interface, that supports multiple extensions while, at the same time, admitting efficient imple- mentations. we illustrate the usefulness of our proposal with concrete examples, and evaluate its cost and performance under different implementation strategies.