Hybrid Strategies for Query Translation and Optimisation
Torsten Grust, Marc H. Scholl · 1998
The advanced data models for PAS that make these systems superior to their table-oriented antecedents (RDBMS) have an impact on the formalisms that are needed to capture these models and their appropiate query languages (eg. ODMG's OQL). Queries that are nested to arbitrary depth, path expressions, and complex predicates pose challenges on the query translation process. The work package RT2.1 will identify generic (algebraic) operators that allow the efficient translation of such queries. These operators will account for the various bulk types the data models feature. Optimisation techniques have to be found, adapted, and validated. PAS query languages allow to mix operations on bulk types and scalars (just like programming languages). Monad calculi treat bulk and scalar types in a uniform way, and allow for reasoning about arithmetics and general computation. This ooeers the perspective of a hybrid approach to query translation and optimisation, combining the power of algebra and calcu...