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Talks DIMA Research Seminar
Talk/Location | Lecturer/Subject |
---|---|
Do. 07.04.2011 16.00 p.m. DIMA EN 719 | Mirek Riegewald t.b.a. |
Mo.
07.02.2011 16.00 p.m. DIMA EN 719 | Kostas
Tzoumas, Aalborg University, Denmark "Representing and exploiting statistical correlations for query processing" |
Mo. 31.01.2011 16.00 p.m. DIMA EN719 | Prof. Dr. habil. Guido Moerkotte,
Universität Mannheim "Approximation unter einem Q-Funktional und Anwendung fuer Kardinalitaetsabschaetzungen in Datenbanksystemen" |
Mo.
17.01.2011 16.00 p.m. DIMA EN 719 | Jens
Dittrich, Chair of Information Systems Group Saarland University "The Hadoop++ Project" |
Mo. 20.12.2010 16.00 p.m. DIMA EN719 | |
Mo. 13.12.2010 16.00 p.m. DIMA EN719 | Geerd-Dietger Hoffmann, TU
Berlin DIMA "Linux / BSD History, Present and Future" |
Mo. 01.11.2010 4 pm DIMA EN719 | Prof. Niels Bjørn-Andersen CAI CT, Copenhagen Business School "Using IT for Creating the 21st Century Organization- The case of Ambient organizations" |
Kostas Tzoumas, Aalborg University, Denmark
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.
Prof. Dr. habil. Guido Moerkotte, Universität Mannheim
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.
Jens Dittrich, Chair of Information Systems Group Saarland University
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]
Geerd-Dietger Hoffmann, TU Berlin DIMA
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.
Prof. Niels Bjørn-Andersen CAI CT, Copenhagen Business School
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.