01 About
Charles Benello
I'm a master's student in Financial Mathematics at the University of Chicago and an incoming tech intern at Alter Domus — with a background in low-level systems research, database internals, and high-performance computing.
I work on large-scale systems and performance engineering, with a recent focus on hardware accelerators — particularly GPUs — and how they can be applied to analytical database workloads. I've published in PVLDB and CIDR, working with Professor Aaron Elmore at UChicago's ChiData Lab and Professor Anastasia Ailamaki at EPFL's DIAS Lab.
Education
University of Chicago
Master's degree / Financial Mathematics
Jun 2025 - Dec 2026
University of Chicago
BS / Mathematics and Computer Science (Systems specialization); Minor in Korean
Sep 2021 - Jun 2025
Dean's List
St Paul's School
2015 - 2021
Mathematics: A*; Further Mathematics: A*; Computer Science: D1
Current Work
- Research: adaptive sort configuration across disaggregated and cloud-native hardware
- Research: GPU-accelerated compression for analytical databases
- Evaluating policy compliance gaps in Rust LLM code generation benchmarks
- CovTSP: near-optimal transit coverage solver using real GTFS network data
- New IDE interface designed around LLM-assisted development workflows
02 Experience
Experience
Database Research Assistant
ChiData Research Lab·Aug 2023 — Present
Two published papers (PVLDB, CIDR) and ongoing research on external sort — building predictive models for sort configuration on disaggregated and cloud-native hardware, with prior work on resource-adaptive query execution and engine internals.
- First-authored CrocSort (PVLDB 2026): a parallel external merge sort that completes under tight memory budgets where PostgreSQL, DuckDB, and ClickHouse abort, by jointly planning memory and phase-specific thread counts
- Co-authored Resource-Adaptive Query Execution with Paged Memory Management (CIDR 2025): enabling query execution to adapt to available memory at runtime
- Building a predictive model for CrocSort's configuration knobs on disaggregated and cloud-native hardware — recommending near-optimal (memory, threads) configs without brute-force sweeps, with small-scale calibration transferring to production within ~3% of optimal
- Implemented Small String Optimization for more compact string storage, reducing memory usage by 40% and improving query speeds
Skills
Papers
03 Research + Publications
Research + Publications
Research Focus
- Large-scale data processing
- Database internals
- High-performance systems
- GPU-accelerated compression
Research Highlights
- Predictive modelling for CrocSort configuration on disaggregated and cloud-native hardware — finding diminishing returns in thread counts and near-optimal config selection without brute-force sweeps
- Resource-adaptive query execution with paged memory management
- GPU-accelerated compression: decompression strategies, workload modelling, and cost-based trade-offs
- Policy gap in Rust code generation benchmarks: showing that code passing SWE-bench tests can still violate project-defined safety and style policies
- Exploring external sort on GPUs, disaggregated hardware, and cloud-native environments — understanding how storage/compute separation and elastic resources reshape sorting performance
Advisors + Labs
- Professor Aaron Elmore (ChiData Lab, University of Chicago)
- Professor Anastasia Ailamaki (DIAS Lab, EPFL)
Publications
CrocSort: Resource-Efficient, Skew-Resilient Parallel External Merge Sort
Riki Otaki*, Charles Benello*, Fuheng Zhao, Aaron J. Elmore, Goetz Graefe
PVLDB 19(1), 2026
* Equal contribution
Sorting Without Guessing: Adaptive Sort Configuration Across Disaggregated and Cloud-Native Environments
Charles Benello, Riki Otaki, Fuheng Zhao, Aaron J. Elmore, Goetz Graefe
HPTS 2026
WIP
Resource-Adaptive Query Execution with Paged Memory Management
Riki Otaki, Jun Hyuk Chang, Charles Benello, Aaron J. Elmore, Goetz Graefe
CIDR 2025
Benchmarks Pass, Policies Fail: A Policy Gap in Rust Code Generation Evaluation
Matt Gaughan, Charles Benello
In preparation
WIP
04 Projects