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• David Lengweiler

David Lengweiler

Research Topics

• Cloud Data Management
• Open Source Software Development

Projects

• Polypheny-DB: Cost- and Workload-aware Adaptive Data Management
• Polypheny-DDI: A Flexible Polystore-based Distributed Data Infrastructure

Lectures

2026 Fall Semester

• DBIS Research Seminar
• Database Systems (cs246)

2026 Spring Semester

• DBIS Research Seminar

2025 Fall Semester

• DBIS Research Seminar
• Database Systems (cs246)
• Introduction to Databases (cs245)

2025 Spring Semester

• DBIS Research Seminar
• Seminar Current Trends in Distributed Systems

2024 Fall Semester

• DBIS Research Seminar
• Database Systems (cs246)
• Introduction to Databases (cs245)

2024 Spring Semester

• DBIS Research Seminar

2023 Fall Semester

• DBIS Research Seminar
• Databases (cs244)
• Introduction to Databases (cs245)

2023 Spring Semester

• DBIS Research Seminar

2022 Fall Semester

• DBIS Research Seminar
• Databases (cs244)

Advised Theses

• Gioia Almer (Bachelor Thesis)
  Heterogenous Data Source Exploring and Tracking in the PolyDBMS architecture
• Christian Hungerbühler (Bachelor Thesis)
  High-Velocity Data Management in the PolyDBMS Architecture
• Luc Heitz (Master Project)
  Sparse Matrix-Based Substitution for Cross-Model Graph Database Mappings
• Mathieu Groenen (Master Project)
  Reproducible & Distributed Heterogenous Data Landscape
• Tobias Martin Weber (Master Thesis)
  Data Pipelines in a PolyDBMS
• Rafael Biehler (Master Thesis)
  Multi-Model Geospatial Queries with Interactive Visualization in a Polystore System
• Daniel Madöry (Bachelor Thesis)
  Multi-Model Stream Processing Benchmark
• Patrik Bütler (Bachelor Thesis)
  Temporal Analysis and Validation of Evaluations
• Tobias Martin Weber (Master Project)
  Textual and Visual Algebra Exploration
• Flurina Fischer (Bachelor Thesis)
  Data Resilience in PolyDBMS Systems
• Tunç Polat (Master Thesis)
  Event-Based Extension of Polypheny for Enhanced Economic Analysis of Token Transfers on the Ethereum Blockchain
• Tobias Martin Weber (Bachelor Thesis)
  Enhancing Jupyter Notebooks with Multi-Model Database Support
• Melanie Svab (Bachelor Thesis)
  Multi-Model Graphical Querying
• Flurina Fischer (Bachelor Project)
  Chameleon Query Interface in Polypheny-DB

Publications

2026

• Marco Vogt, David Lengweiler, Martin Vahlensieck, Yiming Wu, Heiko Schuldt
  From Polystores to Polydbms: The Polypheny Experience
  Proceedings of the 42nd International Conference on Data Engineering (ICDE), Montreal, QC, Canada 2026/5
• David Lengweiler, Marco Vogt, Heiko Schuldt
  Multi-Model Geospatial Data Management and Exploration
  Proceedings of the 42nd International Conference on Data Engineering (ICDE), Montreal, QC, Canada 2026/5
• David Lengweiler, Tobias Weber, Heiko Schuldt, Marco Vogt
  PolyBooks: A System for Interactive Multi-Model Querying with Provenance and Reuse
  Proceedings of the 29th International Conference on Extending Database Technology (EDBT 2026), Tampere, Finland 2026/3
• David Lengweiler, Tobias Weber, Heiko Schuldt, Marco Vogt
  PolyPipe: Merging Data Pipelines and Multi-Model Databases
  Proceedings of the 29th International Conference on Extending Database Technology (EDBT 2026), Tampere, Finland 2026/3

2023

• David Lengweiler, Marco Vogt, Heiko Schuldt
  MMSBench-Net: Scenario-Based Evaluation of Multi-Model Database Systems
  Proceedings of the 34th GI-Workshop on Foundations of Databases (Grundlagen von Datenbanken), Calw, Germany 2023/6

2021

• Marco Vogt, David Lengweiler, Isabel Geissmann, Nils Hansen, Marc Hennemann, Cédric Mendelin, Sebastian Philipp, Heiko Schuldt
  Polystore Systems and DBMSs: Love Marriage or Marriage of Convenience?
  In Proceedings of the 2021 Workshop on “Polystore systems for heterogeneous data in multiple databases with privacy and security assurances” (Poly’21), Copenhagen, Denmark 2021/8

2020

• Marco Vogt, Nils Hansen, Jan Schönholz, David Lengweiler, Isabel Geissmann, Sebastian Philipp, Alexander Stiemer, and Heiko Schuldt
  Polypheny-DB: Towards Bridging the Gap Between Polystores and HTAP Systems
  Proceedings of the 3rd International Workshop on Polystore systems for heterogeneous data in multiple databases with privacy and security assurance (Poly’ 2020), Tokyo, Japan (held virtually) 2020/8

Own Theses

• Persistent and performant schema management in Polypheny-DB (Bachelor Thesis)
• Integrating support for the document data model in a polystore system (Master Project)
• Multi-model Polystore Systems (Master Thesis)
• Heterogeneous Multi-Model Stream Data Management (PhD Thesis)