Publications

Mono Types — First-Class Containers for Datalog

Published in ECOOP, 2025

We propose mono types, a new abstraction for programming Datalog. Mono types behave like first-class containers that can be stored in relations and to which elements can be added decentrally. But, mono types are more than just containers: They provide a read operation that can yield any result as long as it monotonically grows with each added element and is independent of the order in which elements are added to the container. This design permits a wide range of mono types (e.g., sets, maps, and aggregations), yet guarantees mono types can be integrated into Datalog without jeopardizing Datalog’s least fixed-point semantics.

Recommended citation: Runqing Xu, David Klopp, Sebastian Erdweg. (2025). "Mono Types — First-Class Containers for Datalog." ECOOP (2025) . https://doi.org/10.4230/LIPIcs.ECOOP.2025.5

Separate Compilation and Partial Linking: Modules for Datalog IR

Published in GPCE, 2024

In this paper, we present the first module system for a Datalog IR. Our modules are statically typed, can be separately compiled, and partially linked to form “bundles”. Since IR modules are generated by a compiler frontend, we rely on explicit declarations of required and provided relations to maximize the decoupling between modules.

Recommended citation: David Klopp, André Pacak, Sebastian Erdweg. (2024). "Separate Compilation and Partial Linking: Modules for Datalog IR." GPCE (2024) . https://dl.acm.org/doi/10.1145/3689484.3690737

A Typed Multi-level Datalog IR and Its Compiler Framework

Published in OOSPLA, 2024

This paper presents the first compiler framework for Datalog that can be used to support any Datalog frontend language and to target any Datalog backend. The centerpiece of our framework is a novel typed multi-level Datalog IR that supports IR extensions and guarantees executability.

Recommended citation: David Klopp, Sebastian Erdweg, André Pacak. (2024). "A Typed Multi-level Datalog IR and Its Compiler Framework." OOSPLA (2024) . https://dl.acm.org/doi/abs/10.1145/3689767

Object-Oriented Fixpoint Programming with Datalog

Published in OOSPLA, 2024

Modern usages of Datalog exceed its original design purpose in scale and complexity. In particular, Datalog lacks abstractions for code organization and reuse, making programs hard to maintain. Is it possible to exploit abstractions and design patterns from object-oriented programming (OOP) while retaining a Datalog-like fixpoint semantics?

Recommended citation: David Klopp, Sebastian Erdweg, André Pacak. (2024). "Object-Oriented Fixpoint Programming with Datalog." OOSPLA (2024) . https://dl.acm.org/doi/abs/10.1145/3689713

Simurgh: a fully decentralized and secure NVMM user space file system

Published in SC21, 2021

This paper introduces Simurgh, a hardware-assisted user space file system with decentralized metadata management that allows secure metadata updates from within user space.

Recommended citation: Nafiseh Moti, Frederic Schimmelpfennig, Reza Salkhordeh, David Klopp, Toni Cortes, Ulrich Rückert, André Brinkmann. (2021). "Simurgh: a fully decentralized and secure NVMM user space file system." SC21 . https://dl.acm.org/doi/abs/10.1145/3458817.3476180