DBGroup @ SUSTech

The Database Research Group is founded in 2017 and affiliated to Department of Computer Science and Engineering, Southern University of Science and Technology. We conduct in-depth, interesting and insightful researches on data science and engineering, which cover the following aspects:

(1) System: Architect novel data-intensive systems from 0 to 1 (lead by Dr. Bo Tang); (2) Algorithm: Support and accelerate advanced data analytics (lead by Dr. Bo Tang); (3) VIS: Enable intuitive visual understanding of data and systems (lead by Dr. Qiaomu Shen); (4) AI: Improve data analytics and system performance with deep learning (lead by Dr. Dan Zeng).

System

Algorithm

VIS

AI

For more details about our researches, please refer to our publications. We always welcome brilliant people to join DBGroup.

News

2025-04

Our work "ParaGraph: Accelerating Cross-Modal ANNS Indexing via GPU-CPU Parallelism" got accepted to DaMoN 2025. Congratulations to Yuxiang and Bo, special thanks to AlayaDB Inc. for support!

2025-03

Our work "OptMatch: an Efficient and GenericNeural Network-assisted Subgraph Matching Approch" got accepted to ICDE 2025. Congratulations to Wenzhe and Bo

2025-03

We open-sourced the lightweight vector database "AlayaLite", open source address: https://github.com/AlayaDB-AI/AlayaLite. Congratulations to the core development team!

2025-03

Our work "VQLens: A Demonstration of Vector Query Execution Analysis" got accepted to SIGMOD 2025 demo track. Congratulations to Yansha and Bo.

2025-02

Our work "AlayaDB: The Data Foundation for Efficient and Effective Long-context LLM Inference" got accepted to SIGMOD 2025 Industry track. Congratulations to Yangshen and Bo!

See more news

Seminars

Date

Title

Speaker

2025-03-24

Agent Program: Concepts & Practices

Renjie Liu, CS master student at DBGroup in Southern University of Science and Technology (SUSTech)

This seminar covers the key concepts and practices of Agent Programs, which leverage Large Language Models (LLMs) as a core component. We will contrast applications with static workflows (e.g., RAG) against agentic programs with dynamic, runtime decision-making (e.g., ReAct). The discussion will feature the DSPy development framework, the MIPRO technique for automatic prompt optimization, and key evaluation benchmarks like WebVoyager. Finally, we will explore system-level optimizations (e.g., Parrot, Autellix) designed to improve the performance and scheduling for both static and dynamic agentic systems.

2025-03-10

Progressive Sparse Attention: Algorithm and System Co-design for Efficient Attention in LLM Serving

Peiqi Yin, Ph.D. candidate at The Chinese University of Hong Kong (CUHK)

Processing long contexts has become a critical capability for modern large language models (LLMs). However, serving long-context LLMs comes with significant inference costs due to the high memory overhead of the key-value (KV) cache. Existing work leverages dynamic sparse attention algorithms (DSAes) to mitigate the KV cache overhead, but these algorithms rely on top-k KV cache selection, which results in a trade-off between accuracy and efficiency. A larger k improves accuracy but decreases efficiency, while a smaller k boosts efficiency but compromises accuracy. To overcome this trade-off, this paper presents PSA, a Progressive Sparse Attention mechanism that integrates algorithmic innovations with system co-design to achieve both high inference accuracy and improved efficiency in LLM serving. The PSA algorithm adaptively adjusts the KV cache budget of different tokens and layers according to their real attention weight distributions, rather than relying on a fixed budget k. This enables high accuracy while minimizing KV cache usage. To further enhance execution efficiency, we introduce a pipelined iteration scheme that reduces CPU-GPU interleaving and synchronization overhead during PSA computation. Additionally, we implement unified GPU memory management that optimizes PSA's memory utilization by accounting for uneven memory requirements across different model layers. Extensive experimental results demonstrate that PSA reduces KV cache usage for attention computation by up to 2.4× and 8.8×, and increases end-to-end serving throughput by up to 1.4× and 2.0×, compared to state-of-the-art DSAes and systems without sparse attention, respectively.

2025-02-19

PALF: Replicated Write-Ahead Logging for Distributed Databases

徐泉清,北京大学计算机系博士毕业、正高级工程师、蚂蚁技术研究院数据库实验室研究员

近年来,分布式数据库系统因其可扩展性、高可用性和-致性保障而得到了广泛的研究和发展。预写日志系统(WAL)是数据库中最关键的组件之一。设计一个复制的日志系统作为支持ACID 事务的分布式数据库的基础,仍然是一个具有挑战性的问题。我们提出了 PALF(一种基于 Paxos 的仅追加日志文件系统)来解决这些挑战。PALF的核心思想是将日志系统与整个数据库协同设计,以支持数据库特定的功能,并将这些功能抽象为 PALF 原语,从而为其他分布式系统提供支持。许多数据库功能,包括事务处理、数据库恢复和物理备用数据库,都是基于 PALF 原语构建的。实验表明,PALF在性能上显著优于知名的共识协议实现,并且完全能够胜任分布式数据库的工作负载。PALF已作为OceanBase 4.0数据库系统的组件部署,并与其一起开源。
See more seminars

Publications

AlayaDB: The Data Foundation for Efficient and Effective Long-context LLM Inference

Proceedings of the ACM Conference on Management of Data (SIGMOD, CCF-A), 2025

Authors: Yangshen Deng*, Zhengxin You*, Long Xiang*, Qilong Li, Peiqi Yuan, Zhaoyang Hong, Yitao Zheng, Wanting Li, Runzhong Li, Haotian Liu, Kyriakos Mouratidis, Man Lung Yiu, Huan Li, Qiaomu Shen, Rui Mao, Bo Tang

AlayaDB is a cutting-edge vector database system natively architected for efficient and effective long-context inference for Large Language Models (LLMs) at AlayaDB AI. Specifically, it decouples the KV cache and attention computation from the LLM inference systems, and encapsulates them into a novel vector database system. For the Model as a Service providers (MaaS), AlayaDB consumes fewer hardware resources and offers higher generation quality for various workloads with different kinds of Service Level Objectives (SLOs), when comparing with the existing alternative solutions (e.g., KV cache disaggregation, retrieval-based sparse attention). The crux of AlayaDB is that it abstracts the attention computation and cache management for LLM inference into a query processing procedure, and optimizes the performance via a native query optimizer. In this work, we demonstrate the effectiveness of AlayaDB via (i) three use cases from our industry partners, and (ii) extensive experimental results on LLM inference benchmarks.

Tao: Improving Resource Utilization while Guaranteeing SLO in Multi-tenant Relational Database-as-a-Service

Proceedings of the ACM on Management of Data (SIGMOD, CCF-A), 2025

Authors: Haotian Liu, Runzhong Li, Ziyang Zhang, Bo Tang

It is an open challenge for cloud database service providers to guarantee tenants' service-level objectives (SLOs) and enjoy high resource utilization simultaneously. In this work, we propose a novel system Tao to overcome it. Tao consists of three key components: (i) tasklet-based DAG generator, (ii) tasklet-based DAG executor, and (iii) SLO-guaranteed scheduler. The core concept in Tao is tasklet, a coroutine-based lightweight execution unit of the physical execution plan. In particular, we first convert each SQL operator in the traditional physical execution plan into a set of fine-grained tasklets by the tasklet-based DAG generator. Then, we abstract the tasklet-based DAG execution procedure and implement the tasklet-based DAG executor using C++20 coroutines. Finally, we introduce the SLO-guaranteed scheduler for scheduling tenants' tasklets across CPU cores. This scheduler guarantees tenants' SLOs with a token bucket model and improves resource utilization with an on-demand core adjustment strategy. We build Tao on an open-sourced relational database, Hyrise, and conduct extensive experimental studies to demonstrate its superiority over existing solutions.

DiskGNN: Bridging I/O Efficiency and Model Accuracy for Out-of-Core GNN Training

Proceedings of the ACM on Management of Data (SIGMOD, CCF-A), 2025

Authors: Renjie Liu, Yichuan Wang, Xiao Yan, Zhenkun Cai, Minjie Wang, Haitian Jiang, Bo Tang, Jinyang Li.

Graph neural networks (GNNs) are models specialized for graph data and widely used in applications. To train GNNs on large graphs that exceed CPU memory, several systems have been designed to store data on disk and conduct out-of-core processing. However, these systems suffer from either read amplification when conducting random reads for node features that are smaller than a disk page, or degraded model accuracy by treating the graph as disconnected partitions. To close this gap, we build DiskGNN for high I/O efficiency and fast training without model accuracy degradation. The key technique is offline sampling, which decouples graph sampling from model computation. In particular, by conducting graph sampling beforehand for multiple mini-batches, DiskGNN acquires the node features that will be accessed during model computation and conducts pre-processing to pack the node features of each mini-batch contiguously on disk to avoid read amplification for computation. Given the feature access information acquired by offline sampling, DiskGNN also adopts designs including four-level feature store to fully utilize the memory hierarchy of GPU and CPU to cache hot node features and reduce disk access, batched packing to accelerate feature packing during pre-processing, and pipelined training to overlap disk access with other operations. We compare DiskGNN with state-of-the-art out-of-core GNN training systems. The results show that DiskGNN has more than 8× speedup over existing systems while matching their best model accuracy. DiskGNN is open-source at https://github.com/Liu-rj/DiskGNN.

See more publications

Members

Dr. Bo Tang

Dr. Qiaomu Shen

Dr. Dan Zeng

Shiqi Zhang

Ph.D. Candidate

Class of 2019

Jiaping Cao

Ph.D. Candidate

Class of 2020

Wentao Ning

Ph.D. Candidate

Class of 2020

Zheng Bian

Ph.D. Candidate

Class of 2021

Runzhong Li

Ph.D. Candidate

Class of 2021

Jiashuo Lin

Ph.D. Candidate

Class of 2021

Long Xiang

Ph.D. Candidate

Class of 2021

Haotian Liu

Ph.D. Candidate

Class of 2022

Zhengxin You

Ph.D. Candidate

Class of 2022

Bo Huang

MPhil Candidate

Class of 2019

Keming Li

MPhil Candidate

Class of 2020

Qian Li

MPhil Candidate

Class of 2020

Zelin Li

MPhil Candidate

Class of 2021

Chaozu Zhang

MPhil Candidate

Class of 2021

Xiangyu Zhi

MPhil Candidate

Class of 2021

Yangshen Deng

MPhil Candidate

Class of 2022

Qilong Li

MPhil Candidate

Class of 2022

Shangxuan Wu

MPhil Candidate

Class of 2022

See all members

Activities

课题组成员曾剑顺利通过博士学位论文答辩

CCF信息系统专委走进高校系列——走进南方科技大学

2021年表彰大会 照片墙

2020粤港澳大湾区数据库研讨会

DBGroup协助组织南科大附中-计算机系AI夏令营

唐教授与2016级毕业生《我与南科大畅享会》

Collaborators

Contact

We always welcome brilliant people to join our group. If you want to join DBGroup, please fill this form and drop an email to us as soon as possible.

Email

dbgroup_AT_sustech_DOT_edu_DOT_cn

Address

DBGroup, South Tower, CoE Building

Southern University of Science and Technology

Shenzhen, China

Leaflet | © OpenStreetMap contributors