Mediaspace scheduled maintenance: Aug 25, 2026 07:00 - 12:00 AM. During this time, videos will be temporarily unavailable. Check status updates.

Concept

Algèbre relationnelle

Publications associées (21)

Sampling-Based AQP in Modern Analytical Engines

Anastasia Ailamaki, Viktor Sanca

As the data volume grows, reducing the query execution times remains an elusive goal. While approximate query processing (AQP) techniques present a principled method to trade off accuracy for faster queries in analytics, the sample creation is often consid ...

ACM2022

Efficient Massively Parallel Join Optimization for Large Queries

Anastasia Ailamaki, Bikash Chandra, Srinivas Karthik Venkatesh

Modern data analytical workloads often need to run queries over a large number of tables. An optimal query plan for such queries is crucial for being able to run these queries within acceptable time bounds. However, with queries involving many tables, find ...

ACM2022

Edit Based Grading of SQL Queries

Bikash Chandra

Grading student SQL queries manually is a tedious and error-prone process. Earlier work on testing correctness of student SQL queries, such as the XData system, can be used to test the correctness of a student query. However, in case a student query is fou ...

ASSOC COMPUTING MACHINERY2021

Representation Learning for Multi-relational Data

Eda Bayram

Recent years have witnessed a rise in real-world data captured with rich structural information that can be better depicted by multi-relational or heterogeneous graphs. However, research on relational representation learning has so far mostly focused on th ...

EPFL2021

Time- and Space-Efficient Spatial Data Analytics

Mirjana Pavlovic

Advances in data acquisition technologies and supercomputing for large-scale simulations have led to an exponential growth in the volume of spatial data. This growth is accompanied by an increase in data complexity, such as spatial density, but also by mor ...

EPFL2019

Efficient Online Processing for Advanced Analytics

Mohamed Elsayed Mohamed Ahmed El Seidy

With the advent of emerging technologies and the Internet of Things, the importance of online data analytics has become more pronounced. Businesses and companies are adopting approaches that provide responsive analytics to stay competitive in the global ma ...

EPFL2017

Aesthetic Space : The Visible and the Invisible in Urban Agency

Mirza Tursic

Recent 'turns' in social sciences, namely the visual, qualitative, actorial or spatial turns, all indicate a rising interest in individuals. Since the aesthetic dimension always nourishes and informs individualsâ spatialities and their decision-making pr ...

EPFL2017

Squall: Scalable Real-time Analytics

Christoph Koch, Mohammad Dashti Rahmat Abadi, Ioannis Klonatos, Aleksandar Vitorovic, Mohamed Elsayed Mohamed Ahmed El Seidy, Minh Khue Vu

Squall is a scalable online query engine that runs complex analytics in a cluster using skew-resilient, adaptive operators. Squall builds on state-of-the-art partitioning schemes and local algorithms, including some of our own. This paper presents the over ...

VLDB Endowment Inc.2016

Fast Queries Over Heterogeneous Data Through Engine Customization

Anastasia Ailamaki, Manolis Karpathiotakis, Ioannis Alagiannis

Industry and academia are continuously becoming more data-driven and data-intensive, relying on the analysis of a wide variety of heterogeneous datasets to gain insights. The different data models and formats pose a significant challenge on performing anal ...

Assoc Computing Machinery2016

Mobility Intentions of Foreign Researchers: The Role of Non-economic Motivations

Stefano Horst Baruffaldi

Recent contributions suggest that non-economic factors could be important motivational drivers of scientific mobility. We investigate this hypothesis in a sample of foreign researchers in Italy and Portugal, examining their willingness to leave the host co ...

Taylor & Francis2016

Squall: Scalable Real-time Analytics using Efficient, Skew-resilient Join Operators

Aleksandar Vitorovic

Squall is a scalable online query engine that runs complex analytics in a cluster using skew-resilient, adaptive operators. Online processing implies that results are incrementally built as the input arrives, and it is ubiquitous for many applications such ...

EPFL2023

Advancing Analytical Tools to Understand Urban Planning: Mapping Controversies around the Mumbai Development Plan 2014-2034

Luca Giovanni Pattaroni, Salomé Clémentine Houllier-Binder, Tobias Stefan Baitsch-Indermühle, Christine Lutringer-Gully

The proposed article suggests that urban studies are in need of new tools to describe and analyze the different “regimes of urbanization” in an increasingly heterogeneous urban world. In order to create dynamic and relational descriptions of contemporary c ...

2016

TRANSFORMERS: Robust Spatial Joins on Non-Uniform Data Distributions

Anastasia Ailamaki, Thomas Heinis, Farhan Tauheed, Mirjana Pavlovic

Spatial joins are becoming increasingly ubiquitous in many applications, particularly in the scientific domain. While several approaches have been proposed for joining spatial datasets, each of them has a strength for a particular type of density ratio amo ...

IEEE2016

On the Zarankiewicz problem for intersection hypergraphs

János Pach

Let d and t be fixed positive integers, and let denote the complete d-partite hypergraph with t vertices in each of its parts, whose hyperedges are the d-tuples of the vertex set with precisely one element from each part. According to a fundamental theorem ...

Academic Press Inc Elsevier Science2016

Functional Pearl: A SQL to C Compiler in 500 Lines of Code

Tiark Rompf, Nada Amin

We present the design and implementation of a SQL query processor that outperforms existing database systems and is written in just about 500 lines of Scala code - a convincing case study that high-level functional programming can handily beat C for system ...

Assoc Computing Machinery2015

Automated analysis of product related data generated from PLM ontology

Ana Milicic

In recent years, ontology for the Product Lifecycle Management domain has raised a lot of interest in research communities, both academic and industrial. It has emerged as a convenient method for supporting the concept of closed lifecycle information loop, ...

EPFL2015

DBToaster: higher-order delta processing for dynamic, frequently fresh views

Christoph Koch, Amir Shaikhha, Milos Nikolic, Daniel Lupei

Applications ranging from algorithmic trading to scientific data analysis require real-time analytics based on views over databases receiving thousands of updates each second. Such views have to be kept fresh at millisecond latencies. At the same time, the ...

Springer Verlag2014

Mynodbcsv: Lightweight Zero-Config Database Solution for Handling Very Large CSV Files

Volumes of data used in science and industry are growing rapidly. When researchers face the challenge of analyzing them, their format is often the first obstacle. Lack of standardized ways of exploring different data layouts requires an effort each time to ...

2014

Association Generation in Synthetic Population for Transportation Applications: Graph-Theoretic Solution

Michel Bierlaire, Bilal Farooq, Dimitrios Efthymiou

The generation of synthetic populations through simulation methods is an important research topic and has a key application in agent-based modeling of transport and land use. The next step in this research area is the generation of complete synthetic house ...

National Academy of Sciences2014

Jet: An Embedded DSL for High Performance Big Data Processing

Martin Odersky, Tiark Rompf, Vojin Jovanovic, Stefan Ackermann

Cluster computing systems today impose a trade-off between generality, performance and productivity. Hadoop and Dryad force programmers to write low level programs that are tedious to compose but easy to optimize. Systems like Dryad/LINQ and Spark allow co ...

2012