Výsledky vyhľadávania - "Computer Science - Databases"

The Shapley Value of Inconsistency Measures for Functional Dependencies Autor Livshits, Ester, Kimelfeld, Benny

“…Quantifying the inconsistency of a database is motivated by various goals including reliability estimation for new datasets and progress indication in data…”
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Robustness against Read Committed for Transaction Templates with Functional Constraints Autor Vandevoort, Brecht, Ketsman, Bas, Koch, Christoph, Neven, Frank

“…The popular isolation level Multiversion Read Committed (RC) trades some of the strong guarantees of serializability for increased transaction throughput…”
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Ranked Enumeration of Conjunctive Query Results Autor Deep, Shaleen, Koutris, Paraschos

“…We study the problem of enumerating answers of Conjunctive Queries ranked according to a given ranking function. Our main contribution is a novel algorithm…”
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The Shapley Value of Tuples in Query Answering Autor Livshits, Ester, Bertossi, Leopoldo, Kimelfeld, Benny, Sebag, Moshe

“…We investigate the application of the Shapley value to quantifying the contribution of a tuple to a query answer. The Shapley value is a widely known numerical…”
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A Near-Optimal Parallel Algorithm for Joining Binary Relations Autor Ketsman, Bas, Suciu, Dan, Tao, Yufei

“…We present a constant-round algorithm in the massively parallel computation (MPC) model for evaluating a natural join where every input relation has two…”
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Diversity of Answers to Conjunctive Queries Autor Merkl, Timo Camillo, Pichler, Reinhard, Skritek, Sebastian

“…Enumeration problems aim at outputting, without repetition, the set of solutions to a given problem instance. However, outputting the entire solution set may…”
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Refl-Spanners: A Purely Regular Approach to Non-Regular Core Spanners Autor Schmid, Markus L., Schweikardt, Nicole

“…The regular spanners (characterised by vset-automata) are closed under the algebraic operations of union, join and projection, and have desirable algorithmic…”
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Conjunctive Queries with Free Access Patterns under Updates Autor Kara, Ahmet, Nikolic, Milos, Olteanu, Dan, Zhang, Haozhe

“…We study the problem of answering conjunctive queries with free access patterns (CQAPs) under updates. A free access pattern is a partition of the free…”
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Linear Programs with Conjunctive Database Queries Autor Capelli, Florent, Crosetti, Nicolas, Niehren, Joachim, Ramon, Jan

“…In this paper, we study the problem of optimizing a linear program whose variables are the answers to a conjunctive query. For this we propose the language…”
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A Simple Algorithm for Consistent Query Answering under Primary Keys Autor Figueira, Diego, Padmanabha, Anantha, Segoufin, Luc, Sirangelo, Cristina

“…We consider the dichotomy conjecture for consistent query answering under primary key constraints. It states that, for every fixed Boolean conjunctive query q,…”
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Decidability of Querying First-Order Theories via Countermodels of Finite Width Autor Feller, Thomas, Lyon, Tim S., Ostropolski-Nalewaja, Piotr, Rudolph, Sebastian

“…We propose a generic framework for establishing the decidability of a wide range of logical entailment problems (briefly called querying), based on the…”
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Integrity Constraints Revisited: From Exact to Approximate Implication Autor Kenig, Batya, Suciu, Dan

“…Integrity constraints such as functional dependencies (FD) and multi-valued dependencies (MVD) are fundamental in database schema design. Likewise,…”
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Trade-offs in Static and Dynamic Evaluation of Hierarchical Queries Autor Kara, Ahmet, Nikolic, Milos, Olteanu, Dan, Zhang, Haozhe

“…We investigate trade-offs in static and dynamic evaluation of hierarchical queries with arbitrary free variables. In the static setting, the trade-off is…”
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From traditional teaching to flipped classroom: Impact on learning in engineering degrees Autor Aura Hernàndez-Sabaté, Lluís Albarracín, Oriol Ramos, Debora Gil, Carles Sánchez, Enric Martí

“…Computer engineering students should develop competences related to the contents of databases design and SQL queries. For this purpose, the recommendations on…”
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Infinite Probabilistic Databases Autor Grohe, Martin, Lindner, Peter

“…Probabilistic databases (PDBs) model uncertainty in data in a quantitative way. In the established formal framework, probabilistic (relational) databases are…”
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Unbalanced Triangle Detection and Enumeration Hardness for Unions of Conjunctive Queries Autor Bringmann, Karl, Carmeli, Nofar

“…We study the enumeration of answers to Unions of Conjunctive Queries (UCQs) with optimal time guarantees. More precisely, we wish to identify the queries that…”
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The Complexity of Aggregates over Extractions by Regular Expressions Autor Doleschal, Johannes, Kimelfeld, Benny, Martens, Wim

“…Regular expressions with capture variables, also known as regex-formulas, extract relations of spans (intervals identified by their start and end indices) from…”
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Semantic Tree-Width and Path-Width of Conjunctive Regular Path Queries Autor Figueira, Diego, Morvan, Rémi

“…We 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…”
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Enumerating Answers to First-Order Queries over Databases of Low Degree Autor Durand, Arnaud, Schweikardt, Nicole, Segoufin, Luc

“…A class of relational databases has low degree if for all$\delta>0$ , all but finitely many databases in the class have degree at most$n^{\delta}$ , where$n$is…”
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Rewriting with Acyclic Queries: Mind Your Head Autor Geck, Gaetano, Keppeler, Jens, Schwentick, Thomas, Spinrath, Christopher

“…The paper studies the rewriting problem, that is, the decision problem whether, for a given conjunctive query$Q$and a set$\mathcal{V}$of views, there is a…”
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