Zobrazeno 1 - 10
of 154
pro vyhledávání: '"Segoufin, Luc"'
We consider the dichotomy conjecture for consistent query answering under primary key constraints. It states that, for every fixed Boolean conjunctive query q, testing whether q is certain (i.e. whether it evaluates to true over all repairs of a give
Externí odkaz:
http://arxiv.org/abs/2309.12059
We consider the dichotomy conjecture for consistent query answering under primary key constraints. It states that, for every fixed Boolean conjunctive query q, testing whether q is certain (i.e. whether it evaluates to true over all repairs of a give
Externí odkaz:
http://arxiv.org/abs/2301.08482
Autor:
Carmeli, Nofar, Segoufin, Luc
Even though query evaluation is a fundamental task in databases, known classifications of conjunctive queries by their fine-grained complexity only apply to queries without self-joins. We study how self-joins affect enumeration complexity, with the a
Externí odkaz:
http://arxiv.org/abs/2206.04988
Publikováno v:
Logical Methods in Computer Science, Volume 18, Issue 3 (August 2, 2022) lmcs:7110
The program-over-monoid model of computation originates with Barrington's proof that the model captures the complexity class $\mathsf{NC^1}$. Here we make progress in understanding the subtleties of the model. First, we identify a new tameness condit
Externí odkaz:
http://arxiv.org/abs/2101.07495
Publikováno v:
Logical Methods in Computer Science, Volume 18, Issue 2 (May 10, 2022) lmcs:6858
A class of relational databases has low degree if for all $\delta>0$, all but finitely many databases in the class have degree at most $n^{\delta}$, where $n$ is the size of the database. Typical examples are databases of bounded degree or of degree
Externí odkaz:
http://arxiv.org/abs/2010.08382
Autor:
SCHWEIKARDT, NICOLE1 schweikn@informatik.hu-berlin.de, SEGOUFIN, LUC2 luc.segoufin@inria.fr, VIGNY, ALEXANDRE3 vigny@unibremen.de
Publikováno v:
Journal of the ACM. May2022, Vol. 69 Issue 3, p1-37. 37p.
Autor:
Kazana, Wojtek, Segoufin, Luc
Publikováno v:
Logical Methods in Computer Science, Volume 16, Issue 1 (February 25, 2020) lmcs:4281
We consider the evaluation of first-order queries over classes of databases with bounded expansion. The notion of bounded expansion is fairly broad and generalizes bounded degree, bounded treewidth and exclusion of at least one minor. It was known th
Externí odkaz:
http://arxiv.org/abs/1802.04613
Autor:
Figueira, Diego, Segoufin, Luc
Publikováno v:
Logical Methods in Computer Science, Volume 13, Issue 4 (November 6, 2017) lmcs:4044
A data tree is a finite tree whose every node carries a label from a finite alphabet and a datum from some infinite domain. We introduce a new model of automata over unranked data trees with a decidable emptiness problem. It is essentially a bottom-u
Externí odkaz:
http://arxiv.org/abs/1710.08748
A formulation of "Ne\v{c}iporuk's lower bound method" slightly more inclusive than the usual complexity-measure-specific formulation is presented. Using this general formulation, limitations to lower bounds achievable by the method are obtained for s
Externí odkaz:
http://arxiv.org/abs/1608.01932
Autor:
Place, Thomas, Segoufin, Luc
Several years ago Th\'erien and Wilke exhibited a decidable characterization of the languages of words that are definable in FO2(<,+1). Their proof relies on three separate ingredients. The first one is the characterization of the languages that are
Externí odkaz:
http://arxiv.org/abs/1606.03217