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New Results for the Complexity of Resilience for Binary Conjunctive Queries with Self-Joins [article]

Cibele Freire, Wolfgang Gatterbauer, Neil Immerman, Alexandra Meliou
2020 arXiv   pre-print
In this paper, we give several novel results on the hardness of the resilience problem for binary conjunctive queries with self-joins (i.e. conjunctive queries with relations of maximal arity 2) with one  ...  Although restricted, our results provide important insights into the problem of self-joins that we hope can help solve the general case of all conjunctive queries with self-joins in the future.  ...  all self-join conjunctive queries single-self-join (ssj) binary conjunctive queries : ssj binary conjunctive queries with exactly 2 R-atoms ∵ ssj binary conjunctive queries with exactly 3 R-atoms dichotomy  ... 
arXiv:1907.01129v2 fatcat:kvza5tiq4jf3tcixyu4flvjyru

A Characterization of the Complexity of Resilience and Responsibility for Self-join-free Conjunctive Queries [article]

Cibele Freire, Wolfgang Gatterbauer, Neil Immerman, Alexandra Meliou
2015 arXiv   pre-print
In this paper, we study the complexity of resilience for self-join-free conjunctive queries, and also make several contributions to previous known results for the problems of deletion propagation with  ...  source side-effects and causal responsibility: (1) We define the notion of resilience and provide a complete dichotomy for the class of self-join-free conjunctive queries with arbitrary functional dependencies  ...  In order to complete the study of the complexity of resilience for conjunctive queries, we need to investigate the complexity of queries with self-joins.  ... 
arXiv:1507.00674v1 fatcat:cwyebi5xivehpilrvslf32tfb4

From Theory to Practice

Shumo Chu, Magdalena Balazinska, Dan Suciu
2015 Proceedings of the 2015 ACM SIGMOD International Conference on Management of Data - SIGMOD '15  
In this paper, we describe a system that can compute efficiently complex join queries, including queries with cyclic joins, on a massively parallel architecture.  ...  We build on two independent lines of work for multi-join query evaluation: a communication-optimal algorithm for distributed evaluation, and a worst-case optimal algorithm for sequential evaluation.  ...  One advantage of the HyperCube algorithm is that it is more resilient to data skew than a binary join.  ... 
doi:10.1145/2723372.2750545 dblp:conf/sigmod/ChuBS15 fatcat:ozf3ykax5bea5plbrrp7innvfa

Tractable Orders for Direct Access to Ranked Answers of Conjunctive Queries [article]

Nofar Carmeli, Nikolaos Tziavelis, Wolfgang Gatterbauer, Benny Kimelfeld, Mirek Riedewald
2020 arXiv   pre-print
We study the question of when we can answer a Conjunctive Query (CQ) with an ordering over the answers by constructing a structure for direct (random) access to the sorted list of answers, without actually  ...  We begin with the class of lexicographic orderings and give a decidable characterization of the class of feasible such orderings for every CQ without self-joins.  ...  This is due to the fact that this join is a special case of a free-connex Conjunctive Query (CQ).  ... 
arXiv:2012.11965v2 fatcat:pjkge6ep6rh63o4pd4pn76c27m

Logical Aspects of Massively Parallel and Distributed Systems

Frank Neven
2016 Proceedings of the 35th ACM SIGMOD-SIGACT-SIGAI Symposium on Principles of Database Systems - PODS '16  
Here, the focus is on evaluation algorithms for conjunctive queries as well as on reasoning about correctness and optimization of such algorithms.  ...  While distributed and parallel data management systems have been around for quite some time, it is the rise of cloud computing and the advent of Big Data that presents the community with new challenges  ...  I thank Tom Ameloot, Gaetano Geck, Bas Ketsman, Thomas Schwentick, Dan Suciu, and Tony Tan for helpful comments on a previous version of this paper.  ... 
doi:10.1145/2902251.2902307 dblp:conf/pods/Neven16 fatcat:n2ikormeufe7bmy3g5gkbrfcsi

Worst-Case Optimal Algorithms for Parallel Query Processing

Paraschos Koutris, Paul Beame, Dan Suciu, Marc Herbstritt
2016 International Conference on Database Theory  
In this paper, we study the communication complexity for the problem of computing a conjunctive query on a large database in a parallel setting with p servers.  ...  This technique allows us to recover (within a polylogarithmic factor) several recent results on the I/O complexity for computing join queries, and also obtain optimal algorithms for other classes of queries  ...  our result to queries with self-joins (by losing a constant factor) by treating copies of a relation as distinct relations.  ... 
doi:10.4230/lipics.icdt.2016.8 dblp:conf/icdt/KoutrisBS16 fatcat:sniwjhi7pjbxthugucjxgopv2q

GridVine: An Infrastructure for Peer Information Management

Philippe Cudre-Mauroux, Suchit Agarwal, Karl Aberer
2007 IEEE Internet Computing  
The authors discuss a reference implementation of the system and several mechanisms for resolving queries collaboratively. 36 Published by the IEEE Computer Society 1089-7801/07/$25.00 © 2007 IEEE IEEE  ...  This ensures graceful scalability, as new clients entering the system can in turn provide resources and act as servers.  ...  Conjunctive and disjunctive queries can be resolved in a similar manner, 7 by iteratively resolving each triple pattern contained in the query and aggregating the sets of results through local join operations  ... 
doi:10.1109/mic.2007.108 fatcat:x7c2dml6izd7fd4ix7iyulrlgm

Plexus: A Scalable Peer-to-Peer Protocol Enabling Efficient Subset Search

R. Ahmed, R. Boutaba
2009 IEEE/ACM Transactions on Networking  
The concept presented in this paper is supported with theoretical analysis, and simulation results obtained from the application of Plexus to partial keyword search utilizing the extended Golay code.  ...  Plexus achieves better resilience to peer failure by utilizing replication and redundant routing paths. Routing efficiency in Plexus scales logarithmically with the number of superpeers.  ...  For any codeword of a self-dual linear code , , where represents the bit-wise complement of . B. Extended Golay Code The extended Golay code, , is a (24, 12, 8)4 self-dual linear binary code.  ... 
doi:10.1109/tnet.2008.2001466 fatcat:tdahcz46hvcevnujavwalkol6a

Ontology-based peer exchange network(OPEN)

Hui Dong, Zhimin Wang, Robert A. Morris, Jun Huang
2007 2007 International Symposium on Collaborative Technologies and Systems  
Network construction and query model are defined to allow the efficient answer of complex queries based on concepts and relations.  ...  Simulation results are used to verify the predicted network properties.  ...  More complex queries can be composed based on conjunctions.  ... 
doi:10.1109/cts.2007.4621757 dblp:conf/cts/DongWMH07 fatcat:ae3nq735vjdadou4xcgtzr3fnq

Adaptive query processing

A. Deshpande, J. M. Hellerstein, V. Raman
2006 Proceedings of the 2006 ACM SIGMOD international conference on Management of data - SIGMOD '06  
Our goal with this paper is to be a "value-add" over the existing papers on the material, providing not only a brief overview of each technique, but also a basic framework for understanding the field of  ...  This has led to a plethora of new techniques, generally placed under the common banner of adaptive query processing, that focus on using runtime feedback to modify query processing in a way that provides  ...  We are also grateful to our editor, Joe Hellerstein, and the anonymous reviewers of this article for their constructive criticism of the earlier drafts of the article.  ... 
doi:10.1145/1142473.1142603 dblp:conf/sigmod/DeshpandeHR06 fatcat:geklxibgbzdjtix2axmtuhuewu

Assessing the resilience of stochastic dynamic systems under partial observability

Jacopo Panerati, Nicolas Schwind, Stefan Zeltner, Katsumi Inoue, Giovanni Beltrame, Hedvig Kjellström
2018 PLoS ONE  
We show that the time complexity of this algorithm is on par with other state-of-the-art inference queries for similar frameworks (that is, linear with respect to the time horizon).  ...  Resilience is a property of major interest for the design and analysis of generic complex systems.  ...  Acknowledgments The authors would like to thank the reviewers for their comments, the constructive feedback, and the opportunity to improve this manuscript.  ... 
doi:10.1371/journal.pone.0202337 pmid:30138373 fatcat:tave2nw3pzggno3krhdbjqc6au

The RDF-3X engine for scalable management of RDF data

Thomas Neumann, Gerhard Weikum
2009 The VLDB journal  
The query optimizer is able to choose optimal join orders even for complex queries, with a cost model that includes statistical synopses for entire join paths.  ...  The "pay-as-you-go" nature of RDF and the flexible patternmatching capabilities of its query language SPARQL entail efficiency and scalability challenges for complex queries including long join paths.  ...  This calls for specific choices of query processing algorithms, and for careful optimization of complex join queries; but RDF is meant for on-the-fly applications over data spaces, so the optimization  ... 
doi:10.1007/s00778-009-0165-y fatcat:2v5hunczijavfixacbudpsotfi

A case study in building layered DHT applications

Yatin Chawathe, Sriram Ramabhadran, Sylvia Ratnasamy, Anthony LaMarca, Scott Shenker, Joseph Hellerstein
2005 Proceedings of the 2005 conference on Applications, technologies, architectures, and protocols for computer communications - SIGCOMM '05  
In this paper, we explore a case study of building an application for which ease of deployment dominated the need for high performance.  ...  We present Prefix Hash Trees, a data structure use by Place Lab for geographic range queries that is built entire on top of a standard DHT.  ...  The graph shows the total time for the query as well as the time taken for the first item of the results to reach the client. In general, queries with larger responses take longer.  ... 
doi:10.1145/1080091.1080104 dblp:conf/sigcomm/ChawatheRRLSH05 fatcat:og7c6y2qgjdq3gu7smu5tarfxa

A case study in building layered DHT applications

Yatin Chawathe, Sriram Ramabhadran, Sylvia Ratnasamy, Anthony LaMarca, Scott Shenker, Joseph Hellerstein
2005 Computer communication review  
In this paper, we explore a case study of building an application for which ease of deployment dominated the need for high performance.  ...  We present Prefix Hash Trees, a data structure use by Place Lab for geographic range queries that is built entire on top of a standard DHT.  ...  The graph shows the total time for the query as well as the time taken for the first item of the results to reach the client. In general, queries with larger responses take longer.  ... 
doi:10.1145/1090191.1080104 fatcat:pazywlohvrcyvk72hqfp3vltji

Skew in parallel query processing

Paul Beame, Paraschos Koutris, Dan Suciu
2014 Proceedings of the 33rd ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems - PODS '14  
We consider algorithms with one round of communication, and study the complexity of the communication.  ...  We study the problem of computing a conjunctive query q in parallel, using p of servers, on a large database.  ...  For queries with self-joins, the upper bounds hold unchanged, while the lower bounds hold up to constant factor. upper bound on the size of a query answer as a function on the cardinality of the relations  ... 
doi:10.1145/2594538.2594558 dblp:conf/pods/BeameKS14 fatcat:szemzwmkajgofb7dh6yjih4dma
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