Counting answers to unions of conjunctive queries: natural tractability criteria and meta-complexity
We study the problem of counting answers to unions of conjunctive queries (UCQs) under structural restrictions on the input query. Concretely, given a class C of UCQs, the problem #UCQ (C) provides as input a UCQ Ψ ∈ C and a database D and the problem is to compute the number of answers of Ψ in D. &...
| Главные авторы: | , , , |
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| Формат: | Conference item |
| Язык: | English |
| Опубликовано: |
Association for Computing Machinery
2024
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