Talks DIMA Research Seminar

Titel:

"Representing and exploiting statistical correlations for query processing"

Abstract:

Traditional query optimization assumes uniformly distributed data and
statistical independence between attributes. In contrast, real-world
data often exhibits skew and complex correlations. The first part of
the talk presents an approach to discovering and representing
correlations that is based on the theory of graphical models. This
work enables a query optimizer to obtain more accurate selectivity
estimates for conjuncts of join and selection predicates. Further,
statistical correlations can guide the optimizer to select plans that
operate on horizontally partitioned relations and that can be much
cheaper than any plan selected by a traditional optimizer. The second
part of the talk, presents an approach to exploring the space of
horizontally partitioned plans that guarantees maximum sharing of
intermediate results during plan enumeration.

Bio:

Kostas Tzoumas received his Dimploma in Electrical and Computer
Engineering from the National Technical University of Athens, Greece,
in 2007. He is currently a Ph.D. student at Aalborg University,
Denmark. During his Ph.D. studies he has visited the University of
Maryland, College Park and interned twice at Microsoft Research,
Redmond. His research interests include query optimization,
statistical modeling of data, and adaptive index structures.

Titel:

Approximation unter einem Q-Funktional und Anwendung fuer Kardinalitaetsabschaetzungen in Datenbanksystemen

Abstract:

Wir rekapitulieren verschiedene Normen und darauf basierende Fehlermasse und betrachten die Relevanz fuer das Problem der Kardinalitaetsabschaetzung in Datenbanksystemen.
Diese Betrachtung wird ein Quotientenfunktional als Basis fuer die Fehlerdefinition bevorzugen.
Daraufhin stellen wir modifizieren wir einen bekannten Algorithmus, so dass er zu einer optimalen Approximation fuehrt.
Im letzten Schritt betrachten wir dann die Anwendung von Approximation fuer die Kardinalitaetsabschaetzung in Datenbanksystemen.

Bio:

Prof. Dr. habil. Guido Moerkotte leitet die Datenbankforschergruppe in
Mannheim. Vorher war er Professor an der RWTH Aachen.
Er promovierte und habilitierte an der TU Karlsruhe.
Sein Forschungsschwerpunkt ist die Anfrageoptimierung.

Titel:

The Hadoop++ Project

Abstract:

MapReduce is a computing paradigm that has gained a lot of attention in recent years from industry and research. Unlike parallel DBMSs, MapReduce allows non-expert users to run complex analytical tasks over very large data sets on very large clusters and clouds. However, this comes at a price: MapReduce processes tasks in a scan-oriented fashion. Hence, the performance of Hadoop - an open-source implementation of MapReduce - often does not match the one of a well-configured parallel DBMS. We propose a new type of system named Hadoop++: it boosts task performance without changing the Hadoop framework at all. To reach this goal, rather than changing a working system (Hadoop), we inject our technology at the right places through UDFs only and affect Hadoop from inside. This has three important consequences: First, Hadoop++ significantly outperforms Hadoop. Second, any future changes of Hadoop may directly be used with Hadoop++ without rewriting any glue code. Third, Hadoop++ does not need to change the Hadoop interface. Our experiments show the superiority of Hadoop++ over both Hadoop and HadoopDB for tasks related to indexing and join processing. In this talk I will present results from a VLDB 2010 paper as well as more recent work.
Link: infosys.cs.uni-saarland.de/hadoop++.php [1]

Bio:

Since October 2008, Prof. Dittrich chairs the information systems group at Saarland University. He previously held positions at Marburg University (Prof. Bernhard Seeger) , SAP AG (BW and TREX, BI Accelerator), and ETH Zurich (Prof. Donald Kossmann, Systems Group). He published several papers on prestigious database conferences such as VLDB, SIGMOD, and ICDE.
homepage:
infosys.cs.uni-saarland.de/jensdittrich.php [2]

Titel:

Linux / BSD History, Present and Future

Abstract:

This talk will explain the history of the BSD movement and how Linux fits into the bigger picture. An overview over licensing and other important concepts will given and an in-depth discussion of the differences and similarities. To understand modern computers it is vital to understand where the different components come from.
Especially through the rise of mobile computing Linux is moving towards a consumer product and is no longer seen as sole back-end OS.

Bio:

Hoffmann Geerd-Dietger has just completed his MSc in Software Engineering at UCL in London with a first class honours and has just started his PhD at the Technical University of Berlin. Switching between industry, including CERN as well as IBM, and completing his BSc in Bournemouth with a 1st class honours he has engaged in a wide range of topics. He is the creator of the award winning Objic programming language and involved in various Open Source projects. In recent presentations and papers he is showing a growing interest in the future of Cloud Computing.

Titel:

Using IT for Creating the 21st Century Organization - The case of Ambient organizations

Abstract:

IT and telecommunications have always influenced the way companies choose to organize. The future promises of ‘unlimited' processing power, data storage capacity and communication bandwidth for the indi¬vidual will make it more attractive to create new organizational forms. These will need an even stronger focus on core capabilities and a surge in sourcing from other organizations and individuals not on the payroll. This will potentially influence every business process. Cases will be provided, and we shall discuss the way in which the CIO might choreograph and enable this development.



Bio:

Niels is conducting research related to the future ERP systems, inter-organizational systems, and the role of IT in shaping future organizations. Niels has written/edited 25 books, more than 50 peer-reviewed journal articles and more than 100 other publications.
He is a frequently invited speaker at all types of academic and industry events, and is on average contributing once a week to different types of Danish media. He has extensive consulting experience in Denmark and abroad.