LINE: A Learned Index with Group-Enhanced Leaves and Cache-Optimized Inner Tree

Summary: LINE combines linear-model group-enhanced leaves with in-group hashing for locally hard distributions and a cache-aware PLA-built inner tree for global skew. Group-wise SMO migration reduces worst-case tail latency, delivering up to 5.8× improvement. (summarized by gpt-5.6-luna on Jul 26 2026)

Paper ID: h3377c33a14827de8
Venue: SIGMOD
Year: 2026
Pagerank: 4.9605343e-05
Overall Rank: 10,552 | 29.27%
DOI: 10.1145/3802080
PDF: Download (CC BY 4.0)

Incoming Non-self Citations Over Time

No non-self incoming citations found for this paper in this database.

Authors

1. Leying Chen (Chinese Academy of Sciences; University of Chinese Academy of Sciences)
2. Shimin Chen (Chinese Academy of Sciences; University of Chinese Academy of Sciences)

BibTeX Citation

@inproceedings{chen_sigmod26,
        title = {{LINE: A Learned Index with Group-Enhanced Leaves and Cache-Optimized Inner Tree}},
        author = {Chen, Leying and Chen, Shimin},
        series = {{SIGMOD} '26},
        booktitle = {Proceedings of the {ACM} {SIGMOD} International Conference on Management of Data},
        publisher = {Association for Computing Machinery},
        doi = {10.1145/3802080},
        url = {https://dl.acm.org/doi/10.1145/3802080},
        year = {2026}
}

Incoming Citations (Sorted by Pagerank)

Showing 0 of 0 citing papers.

Rank	Citing Paper	Year	Venue	Pagerank

Outgoing Citations (Sorted by Pagerank)

Showing 31 of 31 cited papers.

Citations counted here include only citations to other VLDB/SIGMOD/CIDR/PODS papers in this database.

Rank	Cited Paper	Year	Venue	Pagerank
40	The Case for Learned Index Structures	2018	SIGMOD	0.00046249672
427	ALEX: An Updatable Adaptive Learned Index	2020	SIGMOD	0.00018429918
461	The PGM-index: a fully-dynamic compressed learned index with provable worst-case bounds	2020	VLDB	0.00017835351
550	SageDB: A Learned Database System	2019	CIDR	0.00016525249
774	FITing-Tree: A Data-aware Index Structure	2019	SIGMOD	0.00014063511
870	Learning Multi-dimensional Indexes	2020	SIGMOD	0.0001332034
1,190	Tsunami: A Learned Multi-dimensional Index for Correlated Data and Skewed Workloads	2021	VLDB	0.00011564169
1,328	Building a Bw-Tree Takes More Than Just Buzz Words	2018	SIGMOD	0.00011013165
1,445	LISA: A Learned Index Structure for Spatial Data	2020	SIGMOD	0.00010607118
1,529	Updatable Learned Index with Precise Positions	2021	VLDB	0.00010320909
1,863	LB+-Trees: Optimizing Persistent Index Performance on 3DXPoint Memory	2020	VLDB	9.4679185e-05
1,884	Effectively Learning Spatial Indices	2020	VLDB	9.422145e-05
2,254	FINEdex: A Fine-grained Learned Index Scheme for Scalable and Concurrent Memory Systems	2022	VLDB	8.7429699e-05
2,590	Are Updatable Learned Indexes Ready?	2022	VLDB	8.2368464e-05
2,870	APEX: A High-Performance Learned Index on Persistent Memory	2022	VLDB	7.9033232e-05
3,207	CDFShop: Exploring and Optimizing Learned Index Structures	2020	SIGMOD	7.5187675e-05
3,632	Learned Index: A Comprehensive Experimental Evaluation	2023	VLDB	7.1274345e-05
3,716	CARMI: A Cache-Aware Learned Index with a Cost-based Construction Algorithm	2022	VLDB	7.0541948e-05
4,385	NFL: Robust Learned Index via Distribution Transformation	2022	VLDB	6.613814e-05
4,389	DILI: A Distribution-Driven Learned Index	2023	VLDB	6.6111249e-05
4,656	PLIN: A Persistent Learned Index for Non-Volatile Memory with High Performance and Instant Recovery	2023	VLDB	6.468994e-05
4,915	Can Learned Models Replace Hash Functions?	2023	VLDB	6.3452789e-05
5,353	MxTasks: How to Make Efficient Synchronization and Prefetching Easy	2021	SIGMOD	6.1518275e-05
5,421	FILM: a Fully Learned Index for Larger-than-Memory Databases	2023	VLDB	6.1231965e-05
6,802	SALI: A Scalable Adaptive Learned Index Framework based on Probability Models	2023	SIGMOD	5.6623052e-05
7,103	LITS: An Optimized Learned Index for Strings	2024	VLDB	5.5824915e-05
7,314	Hyper: A High-Performance and Memory-Efficient Learned Index via Hybrid Construction	2024	SIGMOD	5.5425359e-05
8,219	WISK: A Workload-aware Learned Index for Spatial Keyword Queries	2023	SIGMOD	5.359172e-05
8,264	Pea Hash: A Performant Extendible Adaptive Hashing Index	2023	SIGMOD	5.3501391e-05
8,401	Tuning Hierarchical Learned Indexes on Disk and Beyond	2022	SIGMOD	5.3233821e-05
10,222	SWIX: A Memory-efficient Sliding Window Learned Index	2024	SIGMOD	5.0460607e-05

Semantically Similar Papers

#	Overall Rank	Paper	Year	Venue
1	8,401	Tuning Hierarchical Learned Indexes on Disk and Beyond	2022	SIGMOD
2	7,314	Hyper: A High-Performance and Memory-Efficient Learned Index via Hybrid Construction	2024	SIGMOD
3	4,389	DILI: A Distribution-Driven Learned Index	2023	VLDB
4	10,720	HIRE: A Hybrid Learned Index for Robust and Efficient Performance under Mixed Workloads	2026	SIGMOD
5	10,717	From Learning to Recycling: A Log-Structured Learned-Less Index	2026	SIGMOD
6	1,529	Updatable Learned Index with Precise Positions	2021	VLDB
7	6,622	Making In-Memory Learned Indexes Efficient on Disk	2024	SIGMOD
8	6,889	Accelerating String-key Learned Index Structures via Memoization-based Incremental Training	2024	VLDB
9	3,632	Learned Index: A Comprehensive Experimental Evaluation	2023	VLDB
10	834	Benchmarking Learned Indexes	2021	VLDB