Processing queries with quantifiers a horticultural approach
Umeshwar Dayal · 1983
Most research on query processing has focussed on quantifier-free conjunctive queries. Existing techniques for processing queries with quantifiers either compile the query into a nested loop program or use variants of Codd's reduction from the Relational Calculus to the Relational Algebra. In this paper we propose an alternative technique that uses an algebra of graft and prune operations on trees. This technique provides a significant savings in space and time. We show how to transform a quantified conjunctive query into a sequence of graft and prune operations.