Alexander Renz-Wieland

Researcher in the DIMA group at TU Berlin.

Since September 2017, I am a Research Associate and a PhD candidate in the Database Systems and Information Management (DIMA) group at Technische Universität Berlin, supervised by Volker Markl and Rainer Gemulla.

Prior to that, I completed a M. Sc. Business Informatics with a specialization in Data and Web Science at Universität Mannheim, with a semester at VU Amsterdam (with courses from CWI). In my Master's thesis, I worked on scalable sequential pattern mining, supervised by Rainer Gemulla and Kaustubh Beedkar

I obtained my B. Sc. in a dual program at DHBW Mannheim with a semester at Universidad Carlos III Madrid. In this program, I worked for HP in Germany and the U.S.

My current research interest is in large scale machine learning.


Replicate or Relocate? Non-Uniform Access in Parameter Servers
A. Renz-Wieland, R. Gemulla, Z. Kaoudi, V. Markl. preprint (arXiv).
arXiv. source code.

Dynamic Parameter Allocation in Parameter Servers
A. Renz-Wieland, R. Gemulla, S. Zeuch, V. Markl. PVLDB, 13(11): 1877-1890, 2020.
pdf. arXiv. slides. source code.

The DESQ Framework for Declarative and Scalable Frequent Sequence Mining
K. Beedkar, R. Gemulla, A. Renz-Wieland. INFORMATIK '19 (extended abstract).
pdf. slides. source code.

Scalable Frequent Sequence Mining With Flexible Subsequence Constraints
A. Renz-Wieland, M. Bertsch, R. Gemulla. ICDE '19.
pdf. slides. poster. source code.

Distributed frequent sequence mining with declarative subsequence constraints
A. Renz-Wieland. Master's Thesis, University of Mannheim, April 2017.
pdf. slides. source code.

Airport quality: holding and go-arounds
A. Renz-Wieland, H. Wallenburg. Project report for the 2016 LSDE course.
pdf. website.


I was accepted into the Software Campus program, so that the BMBF provides additional funding for my PhD research. If you are a TU student interested in large-scale machine learning, feel free to send me an email.

My M.Sc. faculty honored my master's degree (best 2016/17 degree) and master's thesis (best 2016/17 thesis)


  • Summer semester 2021: Information systems and data analysis (ISDA) and Database seminar (DBSEM)
  • Winter semester 2020/21: Database laboratory (DBPRA)
  • Summer semester 2020: Information systems and data analysis (ISDA)
  • Winter semester 2019/20: Database laboratory (DBPRA)
  • Summer semester 2019: Information systems and data analysis (ISDA)
  • Winter semester 2018/19: Database laboratory (DBPRA)
  • Summer semester 2018: Database laboratory (DBPRA)
  • Winter semester 2017/18: Database laboratory (DBPRA)
Thesis supervision
  • Dynamic parallelism in large-scale graph processing (2019)
  • Lock-Free Data Structures for Locality-Aware Parameter Servers (2019)
  • Benchmarking Probabilistic Programming Languages (2018)

Climate impact

Different aspects of research activity contribute to the climate crisis. One is long-distance travel. Thus, I try to limit travel.

Like others, I think it is reasonable that we report the climate impact of our work. As a step in this direction, please find below a list of flights I have taken so far.

Year Flight Reason CO2 (kg)
2019 Berlin-Peking,
Talk and poster presentation at ICDE,
Talk at ECNU Shanghai
2017 Berlin-Munich,
Meetings with industry partners 216

The CO2 emission estimates are taken from atmosfair. If you have ideas on how to estimate other emissions of research (e.g., computer and cluster usage, office construction and heating), please let me know.

Alexander Renz-Wieland


TU Berlin, FG DIMA
Office EN 709
Einsteinufer 17
10587 Berlin, Germany

+49 30 314 23515

© Alexander Renz-Wieland   |   Last updated: 12 Apr 2021   |   DSGVO imprint