Zobrazeno 1 - 10
of 44
pro vyhledávání: '"Niewerth, Matthias"'
Factorized representations (FRs) are a well-known tool to succinctly represent results of join queries and have been originally defined using the named database perspective. We define FRs in the unnamed database perspective and use them to establish
Externí odkaz:
http://arxiv.org/abs/2309.11663
We describe a framework for maintaining forest algebra representations that are of logarithmic height for unranked trees. Such a representations can be computed in O(n) time and updated in O(log(n)) time. The framework is of potential interest for da
Externí odkaz:
http://arxiv.org/abs/2208.04180
Modern graph database query languages such as GQL, SQL/PGQ, and their academic predecessor G-Core promote paths to first-class citizens in the sense that paths that match regular path queries can be returned to the user. This brings a number of chall
Externí odkaz:
http://arxiv.org/abs/2207.13541
Autor:
Figueira, Diego, Godbole, Adwait, Krishna, S., Martens, Wim, Niewerth, Matthias, Trautner, Tina
Testing containment of queries is a fundamental reasoning task in knowledge representation. We study here the containment problem for Conjunctive Regular Path Queries (CRPQs), a navigational query language extensively used in ontology and graph datab
Externí odkaz:
http://arxiv.org/abs/2003.04411
We consider the information extraction framework known as document spanners, and study the problem of efficiently computing the results of the extraction from an input document, where the extraction task is described as a sequential variable-set auto
Externí odkaz:
http://arxiv.org/abs/2003.02576
Publikováno v:
Logical Methods in Computer Science, Volume 19, Issue 4 (December 7, 2023) lmcs:8604
Regular path queries (RPQs) are an essential component of graph query languages. Such queries consider a regular expression r and a directed edge-labeled graph G and search for paths in G for which the sequence of labels is in the language of r. In o
Externí odkaz:
http://arxiv.org/abs/1903.00226
We give an algorithm to enumerate the results on trees of monadic second-order (MSO) queries represented by nondeterministic tree automata. After linear time preprocessing (in the input tree), we can enumerate answers with linear delay (in each answe
Externí odkaz:
http://arxiv.org/abs/1812.09519
Programs for extracting structured information from text, namely information extractors, often operate separately on document segments obtained from a generic splitting operation such as sentences, paragraphs, k-grams, HTTP requests, and so on. An au
Externí odkaz:
http://arxiv.org/abs/1810.03367
We consider the information extraction framework known as document spanners, and study the problem of efficiently computing the results of the extraction from an input document, where the extraction task is described as a sequential variable-set auto
Externí odkaz:
http://arxiv.org/abs/1807.09320
Publikováno v:
Theoretical Computer Science, 610:91-107, 2016
The downward and upward closures of a regular language $L$ are obtained by collecting all the subwords and superwords of its elements, respectively. The downward and upward interiors of $L$ are obtained dually by collecting words having all their sub
Externí odkaz:
http://arxiv.org/abs/1406.0690