Pesos: a performance evaluation system for object store organizations

One of the most important problems of Object-Oriented Database Management Systems is efficiency. This problem becomes particularly evident with applications managing large amounts of data, with extremely varying structures and sizes (e.g. multimedia data). In order to obtain acceptable performance, it is of crudal importance that the object storage sub system is carefully designed, taking into account both the operational characteristics of the applications and the database characteristics. This paper describes the use of PESOS (Performance Evaluation System for Object Stores), a tool for the evaluation of associative access to very large object stores. PESOS allows the user to describe various object storage organizations in secondary memory, provides a setoriented query language to specify queries on the object store structures, and returns, as a result, a quantitative evaluation (using analytical methods) of the access performance.