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The complexity of evaluating relational queries

Stavros S. Cosmadakis
1983 Information and Control  
A sequence of results which characterize exactly the complexity of problems related to the evaluation of relational queries consisting of projections and natural joins is proved.  ...  The complexity of estimating the number of tuples of the answer is also examined.  ...  ACKNOWLEDGMENTS The author wishes to thank Christos Papadimitriou and Mihalis Yannakakis for many helpful suggestions and comments. RECEIVED April 14, 1983; ACCEPTED August 26, 1983  ... 
doi:10.1016/s0019-9958(83)80059-x fatcat:gsnn2tznabbvzkos4ohdwonniq

Efficient evaluation of n-ary conjunctive queries over trees and graphs

François Bry, Tim Furche, Benedikt Linse, Andreas Schroeder
2006 Proceedings of the eighth ACM international workshop on Web information and data management - WIDM '06  
Furthermore, the approach treats tree and graph-shaped queries uniformly without sacrificing evaluation complexity on the restricted query class.  ...  We propose the first evaluation technique for n-ary conjunctive queries that applies to both tree-and graph-shaped data and retains the same complexity as the best known approaches that are restricted  ...  Unsurprisingly, the shape of the query has a more pronounced effect on the complexity and performance of the evaluation algorithms: Where for path and tree queries the complexity of the evaluation algorithms  ... 
doi:10.1145/1183550.1183555 dblp:conf/widm/BryFLS06 fatcat:3svxmjuvwfe7thly2pv3f43gza

Evaluation of SPARQL Queries Using Relational Databases [chapter]

Jiří Dokulil
2006 Lecture Notes in Computer Science  
Basic storage and querying of RDF data using a relational database can be done in a very simple manner. Such approach can run into trouble when used on large and complex data.  ...  This paper presents such data and several sample queries together with analysis of their performance. It also describes two possible ways of improving the performance based on this analysis.  ...  We used a straightforward way of storing RDF data in a relational database. This allowed us to evaluate SPARQL queries by translating them to SQL queries.  ... 
doi:10.1007/11926078_74 fatcat:3e62qovunjam7gsqpk2xq5dely

Descriptive Complexity Theory for Constraint Databases [chapter]

Erich Grädel, Stephan Kreutzer
1999 Lecture Notes in Computer Science  
The proof of the theorem demonstrates a simple argument for translating complexity results for pre x classes in logical theories to results on the complexity of query evaluation in constraint databases  ...  Considering linear constraints, we show that there is a signi cant gap between the data complexity of rst-order queries on linear constraint databases over the real and the natural numbers.  ...  Dense Linear Orders We now consider the complexity of query evaluation in the context of dense linear orders.  ... 
doi:10.1007/3-540-48168-0_6 fatcat:3nqmsok4erc5zicshsruw27lqe

Complexity of higher-order queries

Huy Vu, Michael Benedikt
2011 Proceedings of the 14th International Conference on Database Theory - ICDT '11  
We give a full picture of the complexity of evaluation for λ-embedded query languages, looking at a number of variations: with negation and without; with only relational algebra operators, and also with  ...  We give tight bounds on both the combined complexity and the query complexity of evaluation in all these settings, in the process explaining connections with Datalog and prior work on λ-calculus evaluation  ...  Benedikt is supported in part by EPSRC EP/G004021/1, EPSRC EP/H017690/1 (the Engineering and Physical Sciences Research Council, UK), and FOX: Foundations of XML -Safe Processing of Dynamic Data over the  ... 
doi:10.1145/1938551.1938579 dblp:conf/icdt/VuB11 fatcat:zplgxl43grfyxamsbgqldsve7a

On the complexity of query answering over incomplete XML documents

Amélie Gheerbrant, Leonid Libkin, Tony Tan
2012 Proceedings of the 15th International Conference on Database Theory - ICDT '12  
The goal of this paper is to provide a complete picture of the complexity of query answering over incomplete XML documents.  ...  To incorporate non-positive features into query languages, we look at gentle ways of introducing negation via inequalities and/or Boolean combinations of positive queries, as well as the analog of relational  ...  For them, we show that the complexity of all the query answering tasks is the same as for relations.  ... 
doi:10.1145/2274576.2274595 dblp:conf/icdt/GheerbrantLT12 fatcat:eed3jiriqbhxhjblhltds2role

Quantum Query Complexity of State Conversion

Troy Lee, Rajat Mittal, Ben W. Reichardt, Robert Špalek, Mario Szegedy
2011 2011 IEEE 52nd Annual Symposium on Foundations of Computer Science  
In the special case of function evaluation, the norm is closely related to the general adversary bound, a semi-definite program that lower-bounds the number of input queries needed by a quantum algorithm  ...  product of the query complexities of the functions, up to a constant.  ...  This follows as quantum query complexity is given by the filtered factorization norm of the difference J − F . • Relation to adversary bound: The semi-definite program giving the filtered factorization  ... 
doi:10.1109/focs.2011.75 dblp:conf/focs/LeeMRSS11 fatcat:csmyuzlshzelrl7yhc6hfxsjue

On the complexity of database queries (extended abstract)

Christos H. Papadimitriou, Mihalis Yannakakis
1997 Proceedings of the sixteenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems - PODS '97  
We appreciate the feedback from the program committee and Moshe Vardi.  ...  of evaluating a query on a database instance, when the query is fixed, and we express the complexity as a function of the size of the database.  ...  It has been noted rather early [14] that, when considering the complexity of evaluating a query on an instance, one has to distinguish between two kinds of complexity: Data complexity is the complexity  ... 
doi:10.1145/263661.263664 dblp:conf/pods/PapadimitriouY97 fatcat:yhhdf7qrffdd5oo66l2cakzbsu

Querying Factorized Probabilistic Triple Databases [chapter]

Denis Krompaß, Maximilian Nickel, Volker Tresp
2014 Lecture Notes in Computer Science  
via sub-query approximations of deterministic views.  ...  An increasing amount of data is becoming available in the form of large triple stores, with the Semantic Web's linked open data cloud (LOD) as one of the most prominent examples.  ...  Acknowledgements Maximilian Nickel acknowledges support by the Center for Brains, Minds and Machines (CBMM), funded by NSF STC award CCF-1231216  ... 
doi:10.1007/978-3-319-11915-1_8 fatcat:j6cakwd6avgu7ln4nt7rmnnyea

Database support for processing complex aggregate queries over data streams

Yuanzhen Ji
2013 Proceedings of the Joint EDBT/ICDT 2013 Workshops on - EDBT '13  
This suggests the feasibility of leveraging database systems to assist SPEs to process complex aggregate queries to reduce their evaluation latency.  ...  (2) efficient evaluation of continuous queries over streaming data that is migrated to the database.  ...  of both types of systems to reduce the per-result evaluation latency of complex aggregate queries.  ... 
doi:10.1145/2457317.2457323 dblp:conf/edbt/Ji13 fatcat:bed45cghjnfaxmvffsc5pkgy4e

Towards a hybrid relational and XML benchmark for loosely-coupled distributed data sources

Mahesh B. Chaudhari, Suzanne W. Dietrich, Jennifer Ortiz, Spencer Pearson
2015 Journal of Systems and Software  
There are known benchmarks for the performance evaluation of relational and XML databases.  ...  Specifically, the paper describes the design of the relational and XML data sources as well as the query redesign in the LINQ query language, which supports queries over heterogeneous data sources.  ...  Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.  ... 
doi:10.1016/j.jss.2015.07.029 fatcat:7xz5miqtbjcabikwdhhothvkwi

Correctness of SQL Queries on Databases with Nulls

Paolo Guagliardo, Leonid Libkin
2017 SIGMOD record  
As a result, the evaluation of SQL queries on databases with nulls may produce answers that are just plain wrong.  ...  However, SQL evaluation can be modified, at least for relational algebra queries, to approximate certain answers, i.e., return only correct answers.  ...  Acknowledgments This survey is based on the work originally published in [15, 25] , which greatly benefited from discussions with  ... 
doi:10.1145/3156655.3156657 fatcat:ayak6sw7zvartmstd4s2kq7nam

Graph Logics with Rational Relations and the Generalized Intersection Problem

Pablo Barcelo, Diego Figueira, Leonid Libkin
2012 2012 27th Annual IEEE Symposium on Logic in Computer Science  
Evaluating formulae in such extended graph logics boils down to checking nonemptiness of the intersection of rational relations with regular or recognizable relations (or, more generally, to the generalized  ...  The primary motivation comes from the study of logics for querying graph topology, which have recently found numerous applications.  ...  This corresponds to the combined complexity of query evaluation.  ... 
doi:10.1109/lics.2012.23 dblp:conf/lics/BarceloFL12 fatcat:wnixhv57lfat5f5ccz3ll7ir74

Database Size Estimation by Query Performance -- A Complexity Aspect

Ye Zhou, Chi-Hung Chi
2012 2012 IEEE Fifth International Conference on Utility and Cloud Computing  
We claim that the relationship between query performance and data size can be captured by a complexity function. One can leverage such function to estimate table size if given query execution time.  ...  Finally, we describe extensive experiments on TPC-W (the most challenging one) to evaluate the effectiveness and efficiency of DSEC in various scenarios.  ...  This work is partially supported by the National Natural Science Foundation of China, under Project Number 61033006.  ... 
doi:10.1109/ucc.2012.9 dblp:conf/ucc/ZhouC12 fatcat:exaqt7r6iradzma5w3ud6yez6e

Querying Big Data by Accessing Small Data

Wenfei Fan, Floris Geerts, Yang Cao, Ting Deng, Ping Lu
2015 Proceedings of the 34th ACM Symposium on Principles of Database Systems - PODS '15  
We study problems for deciding the existence of envelopes and bounded specialized queries, and establish their complexity for various classes of FO queries.  ...  We study boundedly evaluable queries under a form of access constraints, when their evaluation cost is determined by the queries and constraints only.  ...  The complexity of BEP suggests that we develop an effective syntax of boundedly evaluable queries in CQ.  ... 
doi:10.1145/2745754.2745771 dblp:conf/pods/FanGCDL15 fatcat:pzkpmswxlzfmzav6irmrvylsmm
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