Jaechan An

Jaechan An

PhD Student · Computer Science · University of Maryland, College Park
DSLAM (Data Systems Lab)  ·  Advisor: Daniel Abadi

I am a PhD student in Computer Science at the University of Maryland, advised by Daniel Abadi, specializing in distributed database systems. My current research focuses on building low-latency, geo-distributed multi-writer database systems that provide strong consistency.

Previously, I worked on MVCC databases for HTAP workloads and LSM-tree performance optimization at Hanyang University's DBOS Lab, advised by Hyungsoo Jung (now a professor at Seoul National University).

Research

Low-latency Multi-writer Distributed Database Systems with Strong Consistency Current

Developing a geo-distributed multi-writer disaggregated database architecture that provides serializability. The protocol is designed to be concurrency control-agnostic, making it compatible with S2PL, OCC, and MVCC-based systems.

MVCC Databases for Hybrid Transactional/Analytical Processing

Designed and integrated new mechanisms leveraging hardware-assisted (i.e., SmartSSD) and software-based approaches to support HTAP workloads on disk-oriented MVCC databases. Redesigned the GC mechanism to mitigate space amplification, reducing space usage by 93.6% in Sysbench experiments.

Read/Write Amplification in LSM-trees under HTAP

Introduced a new filter layer orthogonal to existing filters (e.g., Bloom filter), reducing read latency by 35.9% in RocksDB. The paper also presents aligned compaction to mitigate write amplification, reducing total disk writes by up to 14.9% under CH-BenCHmark.

Publications

Towards Verifiable Network Telemetry without Special Purpose Hardware

Jaechan An*, Zeying Zhu, Ian Miers, Zaoxing Liu

ACM Workshop on Hot Topics in Networks (HotNets '25)

Deploying Computational Storage for HTAP DBMSs Takes More Than Just Computation Offloading

Kitaek Lee*, Insoon Jo*, Jaechan Ahn*, H. Lee, H. Lee, W. Sul, Hyungsoo Jung  (* co-first authors)

International Conference on Very Large Data Bases (VLDB '23)

DIVA: Making MVCC Systems HTAP-Friendly

Jongbin Kim*, Jaeseon Yu*, Jaechan Ahn, Sooyong Kang, Hyungsoo Jung

ACM SIGMOD International Conference on Management of Data (SIGMOD '22)

Hybrid Transactional/Analytical Processing Amplifies IO in LSM-trees

Jongbin Kim*, Jaechan Ahn, Kitaek Lee, Hyungsoo Jung

IEEE Access (IEEE ACCESS '22)

Teaching

TA · Database Design (CMSC424) · UMD Spring 2025
TA · Database Design (CMSC424) · UMD Fall 2025
TA · Computer and Network Security (CMSC414) · UMD Spring 2025
TA · Cloud Computing (CMSC498B) · UMD Fall 2024
TA · Database Systems · Samsung Summer 2022
TA · Concurrent Programming (ITE4065) · HYU Fall 2021 / 2022
TA · Database Systems (ITE2038) · HYU Fall 2021 / 2022
TA · Operating Systems (ITE3021) · HYU Spring 2021 / 2022