A portrait of Stefan Halfpap

Stefan Halfpap

Research Assistant @ TU Berlin

HPI Alumnus

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Hi 👋

I am a data management researcher and software engineer from Berlin.

Currently, I am a postdoc in the Database Systems and Information Management group of Prof. Markl at TU Berlin.

Before, I was a research assistant in Prof. Plattner's Enterprise Platform and Integration Concepts group at the Hasso Plattner Institute in Potsdam. My dissertation is titled “Integer Linear Programming‐Based Heuristics for Partially Replicated Database Clusters and Selecting Indexes”.

I love my time as a data management researcher, particularly (i) conducting research, (ii) working with other researchers and students, (iii) teaching, and (iv) coding: (i) The reason for my passion for research can be summarized by the following quote of Peter Bailis’ blog post “I loved graduate school”: » [...] by the time you’re done with your dissertation, you’ll have answered questions no one ever answered (or possibly asked) before.« (ii) During my time at university, conferences, and Schloss Dagstuhl, I have met many other enthusiastic and inspiring people. (iii) For me, teaching is a great chance to educate and inspire other people. (iv) Naturally, I also love building software, including contributions to our open‐source platform for evaluating index selection algorithms, supporting the development of the Hyrise database system, and implementing demonstrations of research systems.


Publications

Stefan Halfpap, Jan Kossmann, Rainer Schlosser, Volker Markl:
Looking Deeply into the Magic Mirror: An Interactive Analysis of Database Index Selection Approaches. Proc. VLDB Endow. 17(12): 4301-4304 (2024)

Stefan Halfpap, Rainer Schlosser:
Fragment Allocations for Partially Replicated Databases Considering Data Modifications and Changing Workloads. CIKM 2024: 758-767

Peter A. Boncz, Yannis Chronis, Jan Finis, Stefan Halfpap, Viktor Leis, Thomas Neumann, Anisoara Nica, Caetano Sauer, Knut Stolze, Marcin Zukowski:
SPA: Economical and Workload-Driven Indexing for Data Analytics in the Cloud. ICDE 2023: 3740-3746

Stefan Halfpap:
Hybrid Index Selection Using Integer Linear Programming Based on Cached Cost Estimates of Heuristic Approaches. SiMoD@SIGMOD 2023: 5:1-5:4

Rainer Schlosser, Stefan Halfpap:
Robust and Memory-Efficient Database Fragment Allocation for Large and Uncertain Database Workloads. EDBT 2021: 367-372

Stefan Halfpap, Rainer Schlosser:
Memory-Efficient Database Fragment Allocation for Robust Load Balancing when Nodes Fail. ICDE 2021: 1811-1816

Jan Kossmann, Stefan Halfpap, Marcel Jankrift, Rainer Schlosser:
Magic mirror in my hand, which is the best in the land? An Experimental Evaluation of Index Selection Algorithms. Proc. VLDB Endow. 13(11): 2382-2395 (2020)

Stefan Halfpap, Rainer Schlosser:
Exploration of Dynamic Query-Based Load Balancing for Partially Replicated Database Systems with Node Failures. CIKM 2020: 3409-3412

Rainer Schlosser, Stefan Halfpap:
A Decomposition Approach for Risk-Averse Index Selection. SSDBM 2020: 16:1-16:4

Stefan Klauck, Max Plauth, Sven Knebel, Marius Strobl, Douglas Santry, Lars Eggert:
Eliminating the Bandwidth Bottleneck of Central Query Dispatching Through TCP Connection Hand-Over. BTW 2019: 97-106

Markus Dreseler, Jan Kossmann, Martin Boissier, Stefan Klauck, Matthias Uflacker, Hasso Plattner:
Hyrise Re-engineered: An Extensible Database System for Research in Relational In-Memory Data Management. EDBT 2019: 313-324

Stefan Halfpap, Rainer Schlosser:
Workload-Driven Fragment Allocation for Partially Replicated Databases Using Linear Programming. ICDE 2019: 1746-1749

Stefan Halfpap, Rainer Schlosser:
A Comparison of Allocation Algorithms for Partially Replicated Databases. ICDE 2019: 2008-2011

Stefan Halfpap:
Efficient Scale-Out Using Query-Driven Workload Distribution and Fragment Allocation. PhD@VLDB 2019

Jens Hiller, Maël Kimmerlin, Max Plauth, Seppo HeikkilÀ, Stefan Klauck, Ville Lindfors, Felix Eberhardt, Dariusz Bursztynowski, Jesus Llorente Santos, Oliver Hohlfeld, Klaus Wehrle:
Giving Customers Control Over Their Data: Integrating a Policy Language into the Cloud. IC2E 2018: 241-249

Lars Butzmann, Stefan Klauck, Stephan MĂŒller, Matthias Uflacker, Werner Sinzig, Hasso Plattner:
Generic Business Simulation Using an In-Memory Column Store. BTW 2015: 633-643

Stefan Klauck, Lars Butzmann, Stephan MĂŒller, Martin Faust, David Schwalb, Matthias Uflacker, Werner Sinzig, Hasso Plattner:
Interactive, Flexible, and Generic What-If Analyses Using In-Memory Column Stores. DASFAA (2) 2015: 488-497

Stephan MĂŒller, Anisoara Nica, Lars Butzmann, Stefan Klauck, Hasso Plattner:
Using Object-Awareness to Optimize Join Processing in the SAP HANA Aggregate Cache. EDBT 2015: 557-568

David Schwalb, Jan Kossmann, Martin Faust, Stefan Klauck, Matthias Uflacker, Hasso Plattner:
Hyrise-R: Scale-out and Hot-Standby through Lazy Master Replication for Enterprise Applications. IMDM@VLDB 2015: 7:1-7:7

Stephan MĂŒller, Lars Butzmann, Stefan Klauck, Hasso Plattner:
An Adaptive Aggregate Maintenance Approach for Mixed Workloads in Columnar In-Memory Databases. ACSC 2014: 3-12

Stephan MĂŒller, Lars Butzmann, Stefan Klauck, Hasso Plattner:
Workload-aware aggregate maintenance in columnar in-memory databases. IEEE BigData 2013: 62-69

Stephan MĂŒller, Lars Butzmann, Kai Hoewelmeyer, Stefan Klauck, Hasso Plattner:
Efficient View Maintenance for Enterprise Applications in Columnar In-Memory Databases. EDOC 2013: 249-258

Christian Tinnefeld, Stephan MĂŒller, Helen KaltegĂ€rtner, Sebastian Hillig, Lars Butzmann, David Eickhoff, Stefan Klauck, Daniel Taschik, Björn Wagner, Oliver Xylander, Alexander Zeier, Hasso Plattner, Cafer Tosun:
Available-To-Promise on an In-Memory Column Store. BTW 2011: 667-686


Service

SIGMOD 2026 Program Committee

SIGMOD 2025 Program Committee

BTW 2025 Demo Program Committee

Journal Reviewer VLDBJ 2024

Journal Reviewer VLDBJ 2023