Zobrazeno 1 - 10
of 186
pro vyhledávání: '"Thomas Schwentick"'
Publikováno v:
Logical Methods in Computer Science, Vol Volume 19, Issue 4 (2023)
The paper studies the rewriting problem, that is, the decision problem whether, for a given conjunctive query $Q$ and a set $\mathcal{V}$ of views, there is a conjunctive query $Q'$ over $\mathcal{V}$ that is equivalent to $Q$, for cases where the qu
Externí odkaz:
https://doaj.org/article/208b10847d22474eb403939ed5d18400
Publikováno v:
Logical Methods in Computer Science, Vol Volume 15, Issue 2 (2019)
In the setting of DynFO, dynamic programs update the stored result of a query whenever the underlying data changes. This update is expressed in terms of first-order logic. We introduce a strategy for constructing dynamic programs that utilises period
Externí odkaz:
https://doaj.org/article/d3d63f62da0f41d8b63f78e9ad8bcad9
Autor:
Thomas Schwentick, Thomas Zeume
Publikováno v:
Logical Methods in Computer Science, Vol Volume 8, Issue 1 (2012)
It is shown that the finite satisfiability problem for two-variable logic over structures with one total preorder relation, its induced successor relation, one linear order relation and some further unary relations is EXPSPACE-complete. Actually, EXP
Externí odkaz:
https://doaj.org/article/6719b992f60140b18fa285606a933ced
Autor:
Thomas Schwentick, Nicole Schweikardt
Publikováno v:
Logical Methods in Computer Science, Vol Volume 7, Issue 4 (2011)
This article shows that there exist two particular linear orders such that first-order logic with these two linear orders has the same expressive power as first-order logic with the Bit-predicate FO(Bit). As a corollary we obtain that there also exis
Externí odkaz:
https://doaj.org/article/a2f03ba53df94dcc8ba856f65558ad56
Autor:
Frank Neven, Thomas Schwentick
Publikováno v:
Logical Methods in Computer Science, Vol Volume 2, Issue 3 (2006)
XPath is a simple language for navigating an XML-tree and returning a set of answer nodes. The focus in this paper is on the complexity of the containment problem for various fragments of XPath. We restrict attention to the most common XPath expressi
Externí odkaz:
https://doaj.org/article/32157932affb440c9e4e164debdb8f8c
Autor:
Thomas Schwentick, Klaus Barthelmann
Publikováno v:
Discrete Mathematics & Theoretical Computer Science, Vol 3, Iss 3 (1999)
Building on work of Gaifman [Gai82] it is shown that every first-order formula is logically equivalent to a formula of the form ∃ x 1,...,x l, ∀ y, φ where φ is r-local around y, i.e. quantification in φ is restricted to elements of the univer
Externí odkaz:
https://doaj.org/article/b224e767978f4c2ca28139f3fd107aa1
Publikováno v:
ACM SIGMOD Record. 49:18-29
How can the result of a query be updated after changing a database? This is a fundamental task for database management systems which ideally takes previously computed information into account. In dynamic complexity theory, it is studied from a theore
Publikováno v:
PODS
The ACM PODS Alberto O. Mendelzon Test-of-Time Award is awarded every year to a paper or a small number of papers published in the PODS proceedings ten years prior that had the most impact in terms of research, methodology, or transfer to practice ov
Publikováno v:
Lecture Notes in Computer Science ISBN: 9783030719944
FoSSaCS
FoSSaCS
Which amount of parallel resources is needed for updating a query result after changing an input? In this work we study the amount of work required for dynamically answering membership and range queries for formal languages in parallel constant time
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::78e7176e91140fc4a808bac6066794bd
https://doi.org/10.1007/978-3-030-71995-1_25
https://doi.org/10.1007/978-3-030-71995-1_25
Publikováno v:
Journal of the ACM. 65:1-24
Patnaik and Immerman introduced the dynamic complexity class DynFO of database queries that can be maintained by first-order dynamic programs with the help of auxiliary relations under insertions and deletions of edges. This article confirms their co