Results 21 to 30 of about 1,234 (209)
Query containment for conjunctive queries with regular expressions
ACM SIGACT-SIGMOD-SIGART Symposium on Principles of Database Systems, 1998 All query languages proposed for semistructured data share as common characteristic the ability to traverse arbitrary long path in the data in the form of regular path expressions.
D. Florescu, A. Halevy, Dan Suciu
semanticscholar +2 more sources
Querying the Unary Negation Fragment with Regular Path Expressions [PDF]
International Conference on Database Theory, 2018 The unary negation fragment of first-order logic (UNFO) has recently been proposed as a generalization of modal logic that shares many of its good computational and model-theoretic properties.
J. C. Jung +3 more
semanticscholar +2 more sources
Conjunctive Regular Path Queries in MapReduce
, 2013 In the current big data era, in which we are overloaded with huge amounts of data, there is a large demand for alternatives to traditional querying systems. In our context, big data refers to the petabyte scale data analysis to which industry and academia are ex- posed today; and, where hundreds or thousands of machines, running in parallel, are ...
Ketsman, Bas
openaire +2 more sources
The Complexity of the Shapley Value for Regular Path Queries [PDF]
International Conference on Database Theory, 2022 A path query extracts vertex tuples from a labeled graph, based on the words that are formed by the paths connecting the vertices. We study the computational complexity of measuring the contribution of edges and vertices to an answer to a path query ...
M. Khalil, B. Kimelfeld
semanticscholar +1 more source
A Common Ancestor of PDL, Conjunctive Queries, and Unary Negation First-order
arXiv.orgWe introduce and study UCPDL+, a family of expressive logics rooted in Propositional Dynamic Logic (PDL) with converse (CPDL) and universal modality (UCPDL).
Diego Figueira, Santiago Figueira
semanticscholar +2 more sources
Approximation and Semantic Tree-Width of Conjunctive Regular Path Queries [PDF]
, 2023 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).
Figueira, Diego, Morvan, Rémi
core +1 more source
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 +3 more sources
The Complexity of the Shapley Value for Regular Path Queries [PDF]
, 2023 A path query extracts vertex tuples from a labeled graph, based on the words that are formed by the paths connecting the vertices. We study the computational complexity of measuring the contribution of edges and vertices to an answer to a path query ...
Khalil, Majd, Kimelfeld, Benny
core +1 more source
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 +2 more sources
Performance Guarantees for Distributed Reachability Queries [PDF]
, 2012 In the real world a graph is often fragmented and distributed across different sites. This highlights the need for evaluating queries on distributed graphs.
Wang, Xin +2 more
core