A Logic Query Language and its Algebraic Optimization for a Multiprocessor Database Machine

Abstract

A logic query language, called PRISMAlog, is introduced. The language is one of the interfaces of a multiprocessor, main-memory database machine, called PRISMA. It is a language with a purely declarative semantics; the meaning of a program is given by its least fixed-point. Besides allowing recursive rules, PRISMAlog supports operations like negation, arithmetic, aggregates, and group-by. Optimization of PRISMAlog programs is completely algebraic, and focusses on the use of distributed database techniques to introduce parallelism. Optimization criterion is minimization of response time. Techniques used to optimize PRISMAlog programs and to produce parallel schedules are illustrated. Chapter 1 Introduction In the PRISMA project one of the main research issues is to develop a multiprocessor, main-memory database machine. The research is focussed on the use of distributed database design techniques to achieve a high degree of parallelism, which is used to improve query response time. B..