Conjunctive queries with inequalities under updates
نویسندگان
چکیده
منابع مشابه
Bag Equivalence of Bounded Symmetry-Degree Conjunctive Queries with Inequalities
We consider the problem of checking equivalence of conjunctive queries with inequalities under bag (multiset) semantics. The problem is known to be decidable in pspace and as hard as graph isomorphism, but its exact complexity remains open. We introduce a natural restriction based on what we call the symmetry degree of queries, and show that when the symmetry degree is bounded by a fixed polyno...
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Relational data may have access limitations, i.e., relations may require certain attributes to be selected when they are accessed; this happens, for instance, while querying web data sources (wrapped in relational form) or legacy databases. It is known that the evaluation of a conjunctive query under access limitations requires a recursive algorithm that is encoded into a Datalog program. In th...
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ژورنال
عنوان ژورنال: Proceedings of the VLDB Endowment
سال: 2018
ISSN: 2150-8097
DOI: 10.14778/3192965.3192966