Research Focus & Summary

I am a database systems researcher with extensive experience in designing database features and developing scalable data management solutions. I am currently a Postdoctoral Researcher in the DIMA group at TU Berlin & BIFOLD, working on NebulaStream, an open-source Stream Processing Engine (SPE) for the Cloud-Edge continuum.

I received my PhD, titled "Scalable Management of Complex Spatial Data Types," from the University of Ioannina, where I focused on developing scalable solutions for big spatial data. I am also the principal designer and developer of Hecatoncheir, a high-performance, distributed spatial data–management library built in C++ with MPI.

Key Research Areas

  • Stream Processing: resource-efficient data structures, memory optimization, declarative query processing
  • Spatial Data Management: spatial query optimization, complex spatial data types, polygon approximations, distributed geospatial data management
  • Database Systems: indexing, execution engine, query optimization, concurrency control

Experience

Postdoctoral Researcher
DIMA & BIFOLD, TU Berlin | Berlin, Germany November 2025 – Present
  • Contributing to NebulaStream's codebase and advancing it through research planning.
  • Assisting PhD students with their research.
Doctoral Researcher
MESA: In-memory Spatial Analytics Made Scalable, H.F.R.I. | Ioannina, Greece September 2021 – September 2025
  • Studied and proposed novel solutions for scalable spatial data management.
  • Designed and developed a new high-performance, distributed spatial data management prototype.
  • Fulfilled academic duties such as MSc thesis supervision, lab assistance, and designing/grading assignments.
Research Intern
Archimedes Unit, Athena RC | Athens, Greece July 2024 – July 2025
  • Studied the application of spatial data management solutions to NLP problems.
  • Proposed novel RAG solutions for spatial reasoning tasks over natural language.
Research Intern
Huawei Technologies R&D (UK) Ltd. | Edinburgh, United Kingdom September 2023 – February 2024
  • Designed and implemented query-processing features for a large-scale, production-grade graph database.
  • Addressed concurrency and scalability challenges in a multithreaded database-system environment.

Education

Ph.D. in Computer Science
University of Ioannina | Ioannina, Greece 2025

Dissertation: "Scalable Management of Complex Spatial Data Types"

Integrated M.Sc. in Computer Science
University of Ioannina | Ioannina, Greece 2021

Thesis: "Development of a Prototype Spatial Data-Management System"

Publications

  • Spatial Reasoning using Retrieval-Augmented Generation, T. Georgiadis, J. Pavlopoulos, N. Mamoulis, ACM Transactions on Spatial Algorithms and Systems, 2026 [PDF] [DOI] [Code]
  • Scalable Spatial Topology Joins, T. Georgiadis, N. Mamoulis, EDBT 2026, pp. 110–116 [PDF] [DOI] [Code]
  • Raster Interval Object Approximations for Spatial Intersection Joins, T. Georgiadis, E. Tzirita Zacharatou, N. Mamoulis The VLDB Journal 34(1), pp. 1–25, 2025, [PDF] [DOI] [Code]
  • Hecatoncheir: Scaling up and out Spatial Data Management, T. Georgiadis, A. Michalopoulos, D. Dimitropoulos, D. Tsitsigkos, et al. ACM SIGSPATIAL 2025, [PDF] [DOI] [Code]
  • Raster Intervals: An Approximation Technique for Polygon Intersection Joins, T. Georgiadis, N. Mamoulis, Proceedings of the ACM on Management of Data 1(1), pp. 1–18, SIGMOD 2023 [PDF] [DOI] [Code]
  • Scalable Query Processing on Big Spatial Data, T. Georgiadis, PhD Workshop @ EDBT/ICDT 2023. CEUR-WS Vol. 3379 [PDF]

PC Memberships

2027: ICDE, EDBT, VLDB
2026: VLDB (Demo Track)

Other

2024:
  • Athens NLP 2024 Summer School
2023:
  • 4th ACM Europe Summer School on Data Science
  • Volunteer at EDBT/ICDT 2023 Joint Conference

P.S. See my Google Scholar profile for a more up-to-date publication list. All code associated with my work can be found on my GitHub profile with complete instructions.

Awards

  • 🥉 3rd place Future of Database Programming Contest, March 2025, Athens, Greece [Website]

Music

Sewn Mouth

My band — Modern Metalcore based in Thessaloniki, Greece.

[Links]
Rammen

My bedroom post-rock solo project.

[Bandcamp]