activity
20212026
most citedA Survey on Advancing the DBMS Query Optimizer: Cardinality Estimation, Cost Model, and Plan Enumeration

97 citations · 127 across the 5 of their papers we have counts for

collaborators

7 papers

cs.DB2026

LEARNT: A Practical Estimator for Cardinality of LIKE Queries with Formal Accuracy Guarantees

Hai Lan, Zhifeng Bao, Divesh Srivastava +3

We study the problem of cardinality estimation for LIKE queries on string data, focusing on the most common patterns in real workloads: prefix, suffix, and substring queries. We pr…

cs.DB2026

AgenticScholar: Agentic Data Management with Pipeline Orchestration for Scholarly Corpora

Hai Lan, Tingting Wang, Zhifeng Bao +7

Managing the rapidly growing scholarly corpus poses significant challenges in representation, reasoning, and efficient analysis. An ideal system should unify structured knowledge m…

cs.DB2026

Decomposition-Driven Multi-Table Retrieval and Reasoning for Numerical Question Answering

Feng Luo, Hai Lan, Hui Luo +4

In this paper, we study the problem of numerical multi-table question answering (MTQA) over large-scale table collections (e.g., online data repositories). This task is essential i…

cs.DB2025

Benchmarking RL-Enhanced Spatial Indices Against Traditional, Advanced, and Learned Counterparts

Guanli Liu, Renata Borovica-Gajic, Hai Lan +1

Reinforcement learning has recently been used to enhance index structures, giving rise to reinforcement learning-enhanced spatial indices (RLESIs) that aim to improve query efficie…

cs.DB2023★ 4 cited

A Simple Yet High-Performing On-disk Learned Index: Can We Have Our Cake and Eat it Too?

Hai Lan, Zhifeng Bao, J. Shane Culpepper +2

While in-memory learned indexes have shown promising performance as compared to B+-tree, most widely used databases in real applications still rely on disk-based operations. Based…

cs.DB2023★ 26 cited

Updatable Learned Indexes Meet Disk-Resident DBMS -- From Evaluations to Design Choices

Hai Lan, Zhifeng Bao, J. Shane Culpepper +1

Although many updatable learned indexes have been proposed in recent years, whether they can outperform traditional approaches on disk remains unknown. In this study, we revisit an…