Results 1 to 10 of about 90 (73)
Conjunctive Regular Path Queries with String Variables [PDF]
Proceedings of the 39th ACM SIGMOD-SIGACT-SIGAI Symposium on Principles of Database Systems, 2020 We introduce the class CXRPQ of conjunctive xregex path queries, which are obtained from conjunctive regular path queries (CRPQs) by adding string variables (also called backreferences) as found in practical implementations of regular expressions. CXRPQs can be considered user-friendly, since they combine two concepts that are well-established in ...
Markus L Schmid
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Conjunctive Regular Path Queries with Capture Groups [PDF]
ACM Transactions on Database Systems, 2022 In practice, regular expressions are usually extended by so-called capture groups or capture variables, which allow to capture a subexpression by a variable that can be referenced in the regular expression in order to describe repetitions of subwords. We investigate how this concept could be used for pattern-based graph querying; i.e., we investigate ...
Markus L Schmid
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Semantic Tree-Width and Path-Width of Conjunctive Regular Path Queries [PDF]
Logical Methods in Computer ScienceWe 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).
Diego Figueira, Rémi Morvan
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Expressiveness and static analysis of extended conjunctive regular path queries [PDF]
Journal of Computer and System Sciences, 2013 zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Dominik Freydenberger +1 more
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Conjunctive Regular Path Queries under Injective Semantics
Proceedings of the 42nd ACM SIGMOD-SIGACT-SIGAI Symposium on Principles of Database Systems, 2023 We introduce injective semantics for Conjunctive Regular Path Queries (CRPQs), and study their fundamental properties. We identify two such semantics: atom-injective and query-injective semantics, both defined in terms of injective homomorphisms. These semantics are natural generalizations of the well-studied class of RPQs under simple-path semantics ...
Diego Figueira
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Minimizing Conjunctive Regular Path Queries
Proceedings of the ACM on Management of DataWe study the minimization problem for Conjunctive Regular Path Queries (CRPQs) and unions of CRPQs (UCRPQs). This is the problem of checking, given a query and a number k , whether the query is equivalent to one of size at most k . For CRPQs we consider the size to be the number of atoms, and
Diego Figueira +2 more
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Acyclic Conjunctive Regular Path Queries are no Harder than Corresponding Conjunctive Queries
Proceedings of the ACM on Management of DataWe present an output-sensitive algorithm for evaluating an acyclic Conjunctive Regular Path Query (CRPQ). Its complexity is written in terms of the input size, the output size, and a well-known parameter of the query that is called the ''free-connex fractional hypertree width''.
Dan Suciu +2 more
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Boundedness for Unions of Conjunctive Regular Path Queries over Simple Regular Expressions
Proceedings of the TwentyFirst International Conference on Principles of Knowledge Representation and ReasoningThe problem of whether a recursive query can be rewritten as query without recursion is a fundamental reasoning task, known as the boundedness problem. Here we study the boundedness problem for Unions of Conjunctive Regular Path Queries (UCRPQs), a navigational query language extensively used in ontology and graph database querying.
Diego Figueira +3 more
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Proceedings of the ACM on Management of DataRegular path queries (RPQs) are fundamental for path-constrained reachability analysis, and more complex variants such as conjunctive regular path queries (CRPQs) are increasingly used in graph analytics. Evaluating these queries is computationally expensive, but to the best of our knowledge, no prior work has explored GPU acceleration.
Seohyeon Kim, Min-Soo Kim
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The Dichotomy of Evaluating Homomorphism-Closed Queries on Probabilistic Graphs [PDF]
Logical Methods in Computer Science, 2022 We study the problem of query evaluation on probabilistic graphs, namely, tuple-independent probabilistic databases over signatures of arity two. We focus on the class of queries closed under homomorphisms, or, equivalently, the infinite unions of ...
Antoine Amarilli, İsmail İlkan Ceylan
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