An analytic model in the study of physical database reorganization (abstract only)
Julia E. Hodges · 1985
An analytic model is defined to be used in the study of automated physical database reorganization. Periodic reorganizations are called for so that an acceptable database performance level may be maintained. Database performance is defined in terms of the physical structures which comprise the database. The performance of a particular structure is measured in terms of its storage, retrieval, and update costs. A reorganization is called for when the current performance level, or cost, of the database exceeds the sum of the projected cost (following a reorganization) and the cost of performing a reorganization. Recommendations regarding structural changes are made by the model. The model addresses three such possibilities - the choice of a primary storage structure, the selection of the optimal set of secondary indices, and cleanup of overflow chains. The results of experiments which were conducted using the model are presented. The model is evaluated regarding its usefulness in database performance studies, its generalizability to various database environments, and its extendibility.