Determinacy of Real Conjunctive Queries. The Boolean Case
Jaroslaw Kwiecien, Jerzy Marcinkowski, Piotr Ostropolski-Nalewaja · 2022
In their classical 1993 paper Chaudhuri and Vardi notice that some fundamental database theory results and techniques fail to survive when we try to see query answers as bags (multisets) of tuples rather than as sets of tuples.