Results 11 to 20 of about 2,171,774 (183)
Boundedness of Conjunctive Regular Path Queries [PDF]
CoRR, 2019 We study the boundedness problem for unions of conjunctive regular path queries with inverses (UC2RPQs). This is the problem of, given a UC2RPQ, checking whether it is equivalent to a union of conjunctive queries (UCQ). We show the problem to be ExpSpace-complete, thus coinciding with the complexity of containment for UC2RPQs.
Pablo Barceló +2 more
core +9 more sources
Size Bounds and Algorithms for Conjunctive Regular Path Queries. [PDF]
, 2023 Conjunctive regular path queries (CRPQs) are one of the core classes of queries over graph databases. They are join intensive, inheriting their structure from the relational setting, but they also allow arbitrary length paths to connect points that are to be joined.
Cucumides, Tamara +2 more
core +6 more sources
Conjunctive regular path queries in lightweight description logics
, 2013 Conjunctive regular path queries are an expressive extension of the well-known class of conjunctive queries. Such queries have been extensively studied in the (graph) database community, since they support a controlled form of recursion and enable ...
Magdalena Ortiz, Meghyn Bienvenu
core +5 more sources
Expressive Path Queries on Graph with Data [PDF]
Logical Methods in Computer Science, 2015 Graph data models have recently become popular owing to their applications, e.g., in social networks and the semantic web. Typical navigational query languages over graph databases - such as Conjunctive Regular Path Queries (CRPQs) - cannot express ...
Pablo Barcelo +2 more
doaj +1 more source
Expressiveness and static analysis of extended conjunctive regular path queries [PDF]
, 2011 We study the expressiveness and the complexity of static analysis of extended conjunctive regular path queries (ECRPQs), introduced by Barceló et al. (PODS '10).
Nicole Schweikardt (7168931) +1 more
core +7 more sources
Answering Conjunctive Queries and FO+MOD Queries under Updates [PDF]
, 2020 In dieser Arbeit wird das dynamische Auswertungsproblem über dynamische Datenbanken betrachtet, bei denen Tupel hinzugefügt oder gelöscht werden können. Die Aufgabe besteht darin einen dynamischen Algorithmus zu konstruieren, welcher unmittelbar nachdem ...
Keppeler, Jens
core +1 more source
On (in)tractability of OBDA with OWL 2 QL [PDF]
, 2011 We show that, although conjunctive queries over OWL 2 QL ontologies are reducible to database queries, no algorithm can construct such a reduction in polynomial time without changing the data.
Kikot, Stanislav +2 more
core +8 more sources
Bounded Conjunctive Queries [PDF]
, 2014 A query Q is said to be effectively bounded if for all datasets D, there exists a subset DQ of D such that Q(D) = Q(DQ), and the size of DQ and time for fetching DQ are independent of the size of D. The need for studying such queries is evident, since it
Yu, Wenyuan +3 more
core +1 more source
Complexity of Conjunctive Regular Path Query Homomorphisms
, 2019 15 pages. Short version appeared in the proceedings of the 15th Conference on Computability in Europe (CIE 2019)
Beaudou, Laurent +4 more
openaire +4 more sources
Approximation and Semantic Tree-width of Conjunctive Regular Path Queries.
CoRR, 2022 We show that the problem of whether a query is equivalent to a query of tree-width k is decidable, for the class of Unions of Conjunctive Regular Path Queries with two-way navigation (UC2RPQs). A previous result by Barceló, Romero, and Vardi [Pablo Barceló et al., 2016] has shown decidability for the case k = 1, and here we show that decidability in ...
Figueira, Diego, Morvan, Rémi
openaire +4 more sources