Magic is relevant
Inderpal Singh Mumick, Sheldon J. Finkelstein, Hamid Pirahesh, Raghu Ramakrishnan · 1990
We define the magic-sets transformation for traditional relational systems (with duplicates, aggregation and grouping), as well as for relational systems extended with recursion. We compare the magic-sets rewriting to traditional optimization techniques for nonrecursive queries, and use performance experiments to argue that the magic-sets transformation is often a better optimization technique.