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Semantic Query Processing
Execution and optimisation for queries that combine relational operators with semantic operators backed by learned models.
Data systems · AI4DB · DB4AI
Research Fellow, College of Computing and Data Science
Nanyang Technological University, Singapore
My research focuses on AI for database systems and database systems for AI, especially query optimisation, semantic query processing, and heterogeneous and multimodal data systems.
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I am a Research Fellow at NTU's College of Computing and Data Science. I design algorithms, build database prototypes, and evaluate them under realistic workloads. My work has appeared in ACM SIGMOD, PVLDB, IEEE ICDE, IEEE TKDE, and KDD.
I received my PhD in Computer Science from NTU in March 2026. My doctoral research examined how AI can improve query optimisers while retaining the guarantees and engineering discipline expected from a database system.
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Execution and optimisation for queries that combine relational operators with semantic operators backed by learned models.
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Storage, indexing, and query processing across relational, vector, spatial, text, and image data within the same workload.
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Learning-enhanced and parametric optimisation for concurrent workloads, implemented and evaluated in database systems.
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I am developing execution and optimisation methods for workloads that place model-backed semantic operators in the same plans as conventional relational operators. The work studies database-kernel execution and plan selection when model evaluation is expensive and latency, resource use, and result quality all matter.
Ongoing research; further details will be added as results become public.
This programme examines how learning can replace selected optimisation logic, enhance an existing optimiser, and transfer optimisation knowledge across tasks. I implemented PostgreSQL prototypes that resulted in lemo, RankPQO, and TATA.
In an NTU collaboration with OceanBase, an enterprise-grade distributed database originating from Ant Group, I led the day-to-day technical work on parametric query optimisation. The resulting ScalePQO work was integrated into OceanBase and reported in a PVLDB industry paper.
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2026
PVLDB
Songsong Mo, Quanqing Xu, Xuchen Ding, Yue Zhao, Zhifeng Bao, Chuanhui Yang, and Gao Cong
2026
ICDE
2026
PVLDB
2025
PVLDB
2024
SIGMOD
Songsong Mo, Yile Chen, Hao Wang, Gao Cong, and Zhifeng Bao
2019
KDD
Yipeng Zhang, Yuchen Li, Zhifeng Bao, Songsong Mo, and Ping Zhang · Best Paper Runner-up
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Joined NTU's College of Computing and Data Science as a Research Fellow.
Received my PhD in Computer Science from Nanyang Technological University.
ARCADE appeared at IEEE ICDE 2026.
ScalePQO and TATA appeared in PVLDB.
RankPQO appeared in PVLDB.
The best way to reach me is by email at songsong.mo@ntu.edu.sg.