Optimising and Executing DAPLEX Queries using Prolog
Norman W. Paton · The Computer Journal · 1990
In this paper a query optimiser for use with functional data model databases is described. The system is in use with a large database of protein structures from which examples are taken. The optimiser, which evaluates alternative paths through the object base, is written in Prolog and integrated with a parser for DAPLEX. The constructs of DAPLEX are easily expressed in Prolog, which has also proved suitable for implementing both the parser and rewrite rules. The implementation of the optimiser using rewrite rules is both concise and extensible.