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conjunctive query

Conjunctive Query Answering Under Existential Rules - Decidability, Complexity, and Algorithms

Conjunctive Query Answering Under Existential Rules - Decidability, Complexity, and Algorithms

... answer conjunctive queries with respect to data and a set of rules even if the saturated data associated to them is not of finite ...the conjunctive query answering ...

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A Negative Conjunctive Query is Easy if and only if it is Beta-Acyclic

A Negative Conjunctive Query is Easy if and only if it is Beta-Acyclic

... a query on a structure S can be decided in time O(|S| log |S|)) We extend the easiness result to Signed Conjunctive Query (SCQ) where some atoms are ...

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Combined complexity of probabilistic query evaluation

Combined complexity of probabilistic query evaluation

... α-acyclic conjunctive query Q on an arbitrary instance I in time O(|I| · ...these query parameters to some fixed k makes query evaluation run in time O((|I| · |Q|) f (k) ) for some function f ...

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Schema Query Containment

Schema Query Containment

... that conjunctive query containment is NP-complete. In general, query containment is the problem of checking whether the result of one query is included in the result of another one for any ...

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Efficient Enumeration for Conjunctive Queries over X-underbar Structures

Efficient Enumeration for Conjunctive Queries over X-underbar Structures

... Theorem 4. For every n-ary acyclic conjunctive query Q over an X σ-structure S, Q(S) can be enumerated with a preprocessing O(|S| · |Q|) and a delay O(|Q| · |D|). This delay reduces to O(n·|D|) with a ...

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SPARQL Query Containment under Schema

SPARQL Query Containment under Schema

... of conjunctive query containment has been studied using contain- ment mappings also known as graph homomorphism and canonical ...of) conjunctive queries, query answering and con- tainment are ...

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On Armstrong-compliant Logical Query Languages

On Armstrong-compliant Logical Query Languages

... Declarative query languages for data min- ing have been studied for years [13, 15, 18, ...Logical query languages for data mining have been studied for example in [6, ...general query language for ...

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Differential age-related effects on conjunctive and relational visual short-term memory binding

Differential age-related effects on conjunctive and relational visual short-term memory binding

... interval of 750 ms and a test probe (see Figure 1). For the short-term binding blocks, during the encoding phase, a series of object-colour associations (list length at the participant’s span level) was presented at a ...

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Heuristics-based SPARQL Query Planning

Heuristics-based SPARQL Query Planning

... 1.1 Query & Update published in March ...SPARQL query engines are expected and demanded for retrieving data ...goal query engines usually furnish a query optimizer to undertake the task of ...

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Expressive power of query languages

Expressive power of query languages

... L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignemen[r] ...

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Optimizing FOL reducible query answering

Optimizing FOL reducible query answering

... a query optimization framework for any logical OBDA setting enjoying FOL reducibility of query answering ...duce query answering to the evaluation of alternative FOL queries belonging to richer ...

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Query processing in P2P systems

Query processing in P2P systems

... The query routing is done in a BFS-like way, except that the query is processed only at the peers that are at certain hop distances from the query ...the query must be 2∗r + 1. In other words, ...

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Satisfaction-based Query Load Balancing

Satisfaction-based Query Load Balancing

... with the request. The only two options that satisfy the providers’ preference are p 3 and p 5 , but allocating the query to them may hurt response time. This example illustrates the conflict between providers’ ...

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TQL. A textual query language

TQL. A textual query language

... L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignemen[r] ...

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Cours SQL  (Structured Query Language)

Cours SQL (Structured Query Language)

... SELECT Précise les colonnes qui vont apparaître dans la réponse FROM Précise la (ou les) table intervenant dans l'interrogation WHERE Précise les conditions à appliquer sur les lig[r] ...

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What's beyond query by example?

What's beyond query by example?

... Unité de recherche INRIA Rocquencourt Domaine de Voluceau - Rocquencourt - BP 105 - 78153 Le Chesnay Cedex France Unité de recherche INRIA Futurs : Parc Club Orsay Université - ZAC des V[r] ...

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First Order-Rewritability and Containment of Conjunctive Queries in Horn Description Logics

First Order-Rewritability and Containment of Conjunctive Queries in Horn Description Logics

... of query answering under DL ontologies was first studied in [Calvanese et ...aware query answering using SQL database systems; in fact, the expressive power of DL-Lite is seriously restricted, in this way ...

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Fixed points in conjunctive networks and maximal independent sets in graph contractions

Fixed points in conjunctive networks and maximal independent sets in graph contractions

... of conjunctive networks in the context of gene networks has captured special interest in the last time due to increasing evidence that the synergistic regulation of a gene by several transcription factors, ...

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IRIT-QFR: IRIT Query Feature Resource

IRIT-QFR: IRIT Query Feature Resource

... of query fea- tures associated with TREC adhoc ...of query features: linguistics features that can be calculated from the query itself, prior to any search although some are collection-dependent and ...

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Linguistic features to predict query difficulty

Linguistic features to predict query difficulty

... Each query in these collections was automatically analysed and described with 16 variables, each corresponding to a specific linguistic ...the query as its length and format is the closest to a real user’s ...

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