Filters








285 Hits in 14.8 sec

Answering FO+MOD queries under updates on bounded degree databases [article]

Christoph Berkholz, Jens Keppeler, Nicole Schweikardt
2017 arXiv   pre-print
Our results extend earlier work on the evaluation of first-order queries on static databases of bounded degree and rely on an effective Hanf normal form for FO+MOD recently obtained by Heimberg, Kuske,  ...  We consider queries in first-order logic (FO) and its extension with modulo-counting quantifiers (FO+MOD), and show that they can be efficiently evaluated under updates, provided that the dynamic database  ...  Let ϕ be a fixed k-ary FO`MOD-query and d a fixed degree bound on the databases under consideration.  ... 
arXiv:1702.08764v1 fatcat:nn6svj4osrduzmhguzycf5n73i

Answering FO+MOD Queries under Updates on Bounded Degree Databases

Christoph Berkholz, Jens Keppeler, Nicole Schweikardt
2018 ACM Transactions on Database Systems  
We consider queries in first-order logic (FO) and its extension with modulo-counting quantifiers (FO+MOD), and show that they can be efficiently evaluated under updates, provided that the dynamic database  ...  We extend the known linear time algorithms for first-order logic on classes of databases of bounded degree to the more expressive query language FO+MOD.  ...  ., answering, testing, counting, or enumerating) results of first-order queries on other sparse classes of databases (e.g. planar, bounded treewidth, bounded expansion, nowhere dense) or databases of low  ... 
doi:10.1145/3232056 fatcat:43y7di3muvh3vg6vtzbvij4xdm

Reachability and Distances under Multiple Changes [article]

Samir Datta, Anish Mukherjee, Nils Vortmeier, Thomas Zeume
2018 arXiv   pre-print
In this article we extend the framework to changes of multiple edges at a time, and study the Reachability and Distance queries under these changes.  ...  If the update formulas may use a majority quantifier then both Reachability and Distance can be maintained under changes that affect O(^c n) nodes, for fixed c ∈N.  ...  The goal of a dynamic program is to answer a given query on an input database subjected to changes that insert or delete tuples.  ... 
arXiv:1804.08555v1 fatcat:eydrzofihbcrvlvqtqpjvu3ywa

Dynamic Complexity of Reachability: How Many Changes Can We Handle?

Samir Datta, Pankaj Kumar, Anish Mukherjee, Anuj Tawari, Nils Vortmeier, Thomas Zeume, Emanuela Merelli, Artur Czumaj, Anuj Dawar
2020 International Colloquium on Automata, Languages and Programming  
under insertions.  ...  under changes of polylogarithmic size.  ...  Here we observe that this can be strengthened for changes of polylogarithmic size: a query is in DynFO if, essentially, one can update the query under one polylogarithmic-size change from auxiliary data  ... 
doi:10.4230/lipics.icalp.2020.122 dblp:conf/icalp/DattaK0TVZ20 fatcat:bcnuyzbx4fam3gnh2qkgalvp2e

Dynamic complexity of Reachability: How many changes can we handle? [article]

Samir Datta, Pankaj Kumar, Anish Mukherjee, Anuj Tawari, Nils Vortmeier, Thomas Zeume
2020 arXiv   pre-print
under insertions.  ...  under changes of polylogarithmic size.  ...  The degree of G is bounded by c 1 k +3.  ... 
arXiv:2004.12739v1 fatcat:ml337i6yhbg6hpok3hbr3d7yym

Capturing Missing Tuples and Missing Values

Ting Deng, Wenfei Fan, Floris Geerts
2016 ACM Transactions on Database Systems  
We establish matching lower and upper bounds on these problems for queries expressed in a variety of languages, in each of the three models for specifying relative completeness.  ...  It has been shown that despite missing tuples, such a database may turn out to have complete information for answering a query.  ...  There has also been work on consistent query answering (e.g., [Arenas et al. 1999; Chomicki 2007] ), to find certain answers to a query over all repairs of a database.  ... 
doi:10.1145/2901737 fatcat:iwskktz5kzgnbfnwd352qyykye

The dynamic complexity of transitive closure is in DynTC0

William Hesse
2003 Theoretical Computer Science  
This places dynamic transitive closure in the dynamic complexity class DynTC 0 , and implies that transitive closure can be maintained in database systems that include ÿrst-order update queries and aggregation  ...  All updates and queries can be computed by constant depth threshold circuits of polynomial size (TC 0 circuits).  ...  As part of this, we must show how to update the database on adding or deleting a vertex from the graph.  ... 
doi:10.1016/s0304-3975(02)00740-5 fatcat:jcdbk7gt5bejjk25v3dpefnm4a

Generic Adaptive Moving Object Tracking Algorithms

Jing Zhou, Hong Va Leong, Qin Lu, Ken C.k. Lee
2006 2006 International Conference on Parallel Processing (ICPP'06)  
Moving Object Databases (MODs), the core component of location server to support location-related applications, keep track of the locations of moving objects which submit location update reports to the  ...  In resource-limited wireless environments, the frequency and conditions for generating location update messages exert a strong impact on system performance in terms of update message cost and object location  ...  One typical task is to keep monitoring locations of interested moving objects and log the updated location value to a Moving Object Database (MOD) for centralized efficient query processing.  ... 
doi:10.1109/icpp.2006.46 dblp:conf/icpp/ZhouLLL06 fatcat:effvig23bvbkrfqqxh5jtusfgm

Aggregate Queries on Sparse Databases [article]

Szymon Toruńczyk
2019 arXiv   pre-print
We propose an algebraic framework for studying efficient algorithms for query evaluation, aggregation, enumeration, and maintenance under updates, on sparse databases.  ...  We obtain an optimal algorithm for computing the answers of such queries on sparse databases.  ...  I am very grateful to Luc Segoufin for initiating the discussion on the result (D), and am especially indebted to Micha Pilipczuk, who contributed to initial work towards that result.  ... 
arXiv:1912.12338v1 fatcat:yogzejimmrhxzbis4hsdyaoyzy

Databases and Artificial Intelligence [chapter]

Nicole Bidoit, Patrick Bosc, Laurence Cholvy, Olivier Pivert, Marie-Christine Rousset
2020 A Guided Tour of Artificial Intelligence Research  
It has been shown in 781 Abiteboul and Duschka (1998) that under the soundness assumption on the views 782 extensions, answering Datalog queries from extensions of views defined as con-783 junctive queries  ...  Integrity constraints allow one to control the 283 database evolution and thus checking database consistency arise essentially upon 284 updates. But, when exactly?  ... 
doi:10.1007/978-3-030-06170-8_3 fatcat:j6kir5iut5glxlpntvdp7mdake

First-Order Logic with Counting: At Least, Weak Hanf Normal Forms Always Exist and Can Be Computed! [article]

Dietrich Kuske, Nicole Schweikardt
2017 arXiv   pre-print
, and that allows to compute the size of the query result and to test if a given tuple belongs to the query result within constant time after every database update.  ...  (*) The model checking problem for the fragment FOC(P) of FOCN(P) on structures of bounded degree is fixed-parameter tractable (with elementary parameter dependence). (*) The query evaluation problem  ...  To answer a sentence ϕ under updates, apart from the routines preprocess and update, we aim at a routine answer that outputs ϕ D . The answer time t a is the time used for performing answer.  ... 
arXiv:1703.01122v1 fatcat:2aekogcrpvgstb7lvebiy32ldm

Counting Triangles under Updates in Worst-Case Optimal Time [article]

Ahmet Kara and Hung Q. Ngo and Milos Nikolic and Dan Olteanu and Haozhe Zhang
2019 arXiv   pre-print
We consider the problem of incrementally maintaining the triangle count query under single-tuple updates to the input relations.  ...  This lowest update time is worst-case optimal conditioned on the Online Matrix-Vector Multiplication conjecture.  ...  We design IVM ǫ strategies that maintain 3R queries in worst-case optimal time (conditioned on the OMv conjecture). We  ... 
arXiv:1804.02780v2 fatcat:zo7o54sugndk7fa4rnlhf5ptti

Dynamic Complexity Meets Parameterised Algorithms [article]

Jonas Schmidt, Thomas Schwentick, Nils Vortmeier, Thomas Zeume, Ioannis Kokkinis
2019 arXiv   pre-print
Dynamic Complexity studies the maintainability of queries with logical formulas in a setting where the underlying structure or database changes over time.  ...  More detail is given in the appendix. ◭ The following lemma basically states that every boolean parameterised query can be answered in para-S-FO on instances whose domain size is bounded by a function  ...  The class DynFO is the set of dynamic queries that can be maintained by a dynamic program with first-order update formulas. The class DynFO(+, ×) is defined analogously via FO(+,×) update formulas.  ... 
arXiv:1910.06281v2 fatcat:kqxvs46ed5cblkuj2liutee2m4

Inconsistency-tolerant query answering in ontology-based data access

Domenico Lembo, Maurizio Lenzerini, Riccardo Rosati, Marco Ruzzi, Domenico Fabio Savo
2015 Journal of Web Semantics  
during query answering, by relying on the notion of database repair.  ...  Our work is inspired by the approaches to consistent query answering in databases, which are based on the idea of living with inconsistencies in the database, but trying to obtain only consistent information  ...  This research has been partially supported by the EU under FP7 project Optique -Scalable End-user Access to Big Data (grant n. FP7-318338).  ... 
doi:10.1016/j.websem.2015.04.002 fatcat:kcrhpvmymzaonmngkey5i43pkq

Maintaining Triangle Queries under Updates [article]

Ahmet Kara, Milos Nikolic, Hung Q. Ngo, Dan Olteanu, Haozhe Zhang
2020 arXiv   pre-print
We consider the problem of incrementally maintaining the triangle queries with arbitrary free variables under single-tuple updates to the input relations.  ...  It is strongly Pareto optimal for the triangle queries with zero or three free variables and weakly Pareto optimal for the triangle queries with one or two free variables.  ...  As the database evolves under updates, IVM ǫ needs to rebalance the relation partitions to account for updated degrees of data values.  ... 
arXiv:2004.03716v1 fatcat:e6x6i3i5ozgqve7bom3ts6vikm
« Previous Showing results 1 — 15 out of 285 results