Learning to be a Statistician: Learned Estimator for Number of Distinct Values

Summary: Proposes a supervised-learning NDV estimator, replacing heuristic sample methods with a data-driven model. Trains on synthetic data for workload-agnostic deployment as a UDF, outperforming existing estimators on nine real datasets; code available. (summarized by gpt-5-nano on Feb 09 2026)

Paper ID: 12947
Venue: VLDB
Year: 2022
Pagerank: 5.6540503e-05
Overall Rank: 7,290 | 49.99%
DOI: 10.14778/3489496.3489508

Incoming Non-self Citations Over Time

Authors

1. Renzhi Wu (Georgia Institute of Technology)
2. Bolin Ding (Alibaba)
3. Xu Chu (Georgia Institute of Technology)
4. Zhewei Wei (Renmin University of China)
5. Xiening Dai (Alibaba)
6. Tao Guan (Alibaba)
7. Jingren Zhou (Alibaba)

BibTeX Citation

@article{wu_vldb22,
        title = {{Learning to be a Statistician: Learned Estimator for Number of Distinct Values}},
        author = {Wu, Renzhi and Ding, Bolin and Chu, Xu and Wei, Zhewei and Dai, Xiening and Guan, Tao and Zhou, Jingren},
        journal = {PVLDB},
        series = {{VLDB} '22},
        volume = {15},
        number = {2},
        pages = {272--284},
        doi = {10.14778/3489496.3489508},
        url = {https://doi.org/10.14778/3489496.3489508},
        year = {2022}
}

Incoming Citations (Sorted by Pagerank)

Showing 9 of 9 citing papers.

Rank	Citing Paper	Year	Venue	Pagerank
6,462	PilotScope: Steering Databases with Machine Learning Drivers	2024	VLDB	5.8717744e-05
6,543	Speeding Up End-to-end Query Execution via Learning-based Progressive Cardinality Estimation	2023	SIGMOD	5.8461929e-05
7,193	dbET: Execution Time Distribution-based Plan Selection	2023	SIGMOD	5.6770249e-05
8,849	ByteCard: Enhancing ByteDance’s Data Warehouse with Learned Cardinality Estimation	2024	SIGMOD	5.3577504e-05
8,850	Learning-based Property Estimation with Polynomials	2024	SIGMOD	5.3577504e-05
9,560	Ground Truth Inference for Weakly Supervised Entity Matching	2023	SIGMOD	5.2528121e-05
9,971	Athena: An Effective Learning-based Framework for Query Optimizer Performance Improvement	2025	SIGMOD	5.1845938e-05
10,774	PLM4NDV: Minimizing Data Access for Number of Distinct Values Estimation with Pre-trained Language Models	2025	SIGMOD	5.093636e-05
10,806	AdaNDV: Adaptive Number of Distinct Value Estimation via Learning to Select and Fuse Estimators	2025	VLDB	5.093636e-05

Outgoing Citations (Sorted by Pagerank)

Showing 13 of 13 cited papers.

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

Rank	Cited Paper	Year	Venue	Pagerank
75	Sampling-Based Estimation of the Number of Distinct Values of an Attribute	1995	VLDB	0.00037277061
84	Learned Cardinalities: Estimating Correlated Joins with Deep Learning	2019	CIDR	0.00035838391
288	Towards Estimation Error Guarantees for Distinct Values	2000	PODS	0.00022296371
323	DeepDB: Learn from Data, not from Queries!	2020	VLDB	0.00021264788
697	Selectivity Estimation for Range Predicates using Lightweight Models	2019	VLDB	0.00014888851
1,061	Are We Ready For Learned Cardinality Estimation?	2021	VLDB	0.00012369764
1,108	Approximate Query Processing: No Silver Bullet	2017	SIGMOD	0.00012145154
1,516	Cardinality Estimation: An Experimental Survey	2018	VLDB	0.00010520885
1,988	FLAT: Fast, Lightweight and Accurate Method for Cardinality Estimation	2021	VLDB	9.3501502e-05
2,203	Estimating Join Selectivities using Bandwidth-Optimized Kernel Density Models	2017	VLDB	8.9610447e-05
2,281	Selectivity Estimation in Extensible Databases - A Neural Network Approach	1998	VLDB	8.8129279e-05
3,162	Efficiently Approximating Selectivity Functions using Low Overhead Regression Models	2020	VLDB	7.6785856e-05
5,998	Approximate Distinct Counts for Billions of Datasets	2019	SIGMOD	6.0142553e-05

Semantically Similar Papers

#	Overall Rank	Paper	Year	Venue
1	4,368	Lightweight and Accurate Cardinality Estimation by Neural Network Gaussian Process	2022	SIGMOD
2	1,573	Deep Learning Models for Selectivity Estimation of Multi-Attribute Queries	2020	SIGMOD
3	10,774	PLM4NDV: Minimizing Data Access for Number of Distinct Values Estimation with Pre-trained Language Models	2025	SIGMOD
4	2,543	Learned Cardinality Estimation: An In-depth Study	2022	SIGMOD
5	75	Sampling-Based Estimation of the Number of Distinct Values of an Attribute	1995	VLDB
6	1,061	Are We Ready For Learned Cardinality Estimation?	2021	VLDB
7	288	Towards Estimation Error Guarantees for Distinct Values	2000	PODS
8	2,723	Learned Cardinality Estimation: A Design Space Exploration and A Comparative Evaluation	2022	VLDB
9	8,850	Learning-based Property Estimation with Polynomials	2024	SIGMOD
10	10,806	AdaNDV: Adaptive Number of Distinct Value Estimation via Learning to Select and Fuse Estimators	2025	VLDB