Concept

Datalog

Publications associées (38)

Graph Chatbot

Chattez avec Graph Search

Posez n’importe quelle question sur les cours, conférences, exercices, recherches, actualités, etc. de l’EPFL ou essayez les exemples de questions ci-dessous.

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ConDense: Managing Data in Community-driven Mobile Geosensor Networks

Karl Aberer, Dipanjan Chakraborty, Saket Sathe, Sebastian Cartier

Effectively managing the data generated by community-driven mobile geo-sensor networks is a new and challenging problem. One important step for managing and querying sensor network data is to create abstractions of the data in the form of models. These mod ...

2012

Predictable performance and high query concurrency for data analytics

George Candea

Conventional data warehouses employ the query- at-a-time model, which maps each query to a distinct physical plan. When several queries execute concurrently, this model introduces contention and thrashing, because the physical plans—unaware of each other—c ...

2011

On Probabilistic Fixpoint and Markov Chain Query Languages.

Christoph Koch

We study highly expressive query languages such as datalog, fixpoint, and while-languages on probabilistic databases. We generalize these languages such that computation steps (e.g. datalog rules) can fire probabilistically. We define two possible semantic ...

2010

Incremental Query Evaluation in a Ring of Databases.

Christoph Koch

This paper approaches the incremental view maintenance problem from an algebraic perspective. We construct a ring of databases and use it as the foundation of the design of a query calculus that allows to express powerful aggregate queries. The query calcu ...

2010

Efficient Processing of Ranking Queries in Novel Applications

Parisa Haghani

Ranking queries, which return only a subset of results matching a user query, have been studied extensively in the past decade due to their importance in a wide range of applications. In this thesis, we study ranking queries in novel environments and setti ...

EPFL2010

Approximate Confidence Computation in Probabilistic Databases.

Christoph Koch

This paper introduces a deterministic approximation algorithm with error guarantees for computing the probability of propositional formulas over discrete random variables. The algorithm is based on an incremental compilation of formulas into decision diagr ...

2010

Generalized Hypertree Decompositions: NP-hardness and Tractable Variants

Zoltán Miklós

The generalized hypertree width GHW(H) of a hypergraph H is a measure of its cyclicity. Classes of conjunctive queries or constraint satisfaction problems whose associated hypergraphs have bounded GHW are known to be solvable in polynomial time. However, i ...

2009

A Scalable, Predictable Join Operator for Highly Concurrent Data Warehouses

George Candea

Conventional data warehouses employ the query-at-a-time model, which maps each query to a distinct physical plan. When several queries execute concurrently, this model introduces contention, because the physical plans—unaware of each other—compete for acce ...

2009

Contextualized and personalized location-based services

Shijun Yu

Advances in the technologies of smart mobile devices and tiny sensors together with the increase in the number of web resources open up a plethora of new mobile information services where people can acquire and disseminate information at any place and any ...

EPFL2008

Two-handed gestures for human-computer interaction

Agnès Just

The present thesis is concerned with the development and evaluation (in terms of accuracy and utility) of systems using hand postures and hand gestures for enhanced Human-Computer Interaction (HCI). In our case, these systems are based on vision techniques ...

EPFL2007