Still Asking: How Good Are Query Optimizers, Really?

Summary: Introduces the Join Order Benchmark (JOB) and an empirical methodology to disentangle plan enumeration, cost modeling, and cardinality estimation contributions to optimizer quality. Finds pervasive cardinality-estimation errors dominate bad plans, spurring research on learned estimators, robustness, adaptive execution, and realistic workloads. (summarized by gpt-5-mini on Feb 09 2026)

Paper ID: 14198
Venue: VLDB
Year: 2025
Pagerank: 4.2856385e-05
Overall Rank: 9,746 | 32.27%
DOI: 10.14778/3750601.3760521

Incoming Non-self Citations Over Time

Authors

Incoming Citations (Sorted by Pagerank)

Showing 1 of 1 citing papers.

Rank	Citing Paper	Year	Venue	Pagerank
9,987	I Can't Believe It's Not Yannakakis: Pragmatic Bitmap Filters in Microsoft SQL Server	2026	CIDR	4.1905499e-05

Outgoing Citations (Sorted by Pagerank)

Showing 35 of 35 cited papers.

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

Rank	Cited Paper	Year	Venue	Pagerank
1	Access Path Selection in a Relational Database Management System	1979	SIGMOD	0.0040465394
71	How Good Are Query Optimizers, Really?	2016	VLDB	0.00059446482
181	LEO - DB2's LEarning Optimizer	2001	VLDB	0.00036970794
203	Learned Cardinalities: Estimating Correlated Joins with Deep Learning	2019	CIDR	0.00034868567
329	Neo: A Learned Query Optimizer	2019	VLDB	0.00027301488
454	An Overview of Query Optimization in Relational Systems	1998	PODS	0.00022796106
530	The LDBC Social Network Benchmark: Interactive Workload	2015	SIGMOD	0.00020823189
606	DeepDB: Learn from Data, not from Queries!	2020	VLDB	0.00019251186
634	Bao: Making Learned Query Optimization Practical	2021	SIGMOD	0.00018844568
905	NeuroCard: One Cardinality Estimator for All Tables	2021	VLDB	0.00015423174
1,334	Optimizing Subgraph Queries by Combining Binary and Worst-Case Optimal Joins	2019	VLDB	0.00012543633
1,638	Cardinality Estimation in DBMS: A Comprehensive Benchmark Evaluation	2022	VLDB	0.00011050093
1,699	Are We Ready For Learned Cardinality Estimation?	2021	VLDB	0.00010848882
2,154	SkinnerDB: Regret-Bounded Query Evaluation via Reinforcement Learning	2018	VLDB	9.4176683e-05
2,281	Adopting Worst-Case Optimal Joins in Relational Database Systems	2020	VLDB	9.122455e-05
2,359	Consistently Estimating the Selectivity of Conjuncts of Predicates	2005	VLDB	8.967267e-05
2,781	Flow-Loss: Learning Cardinality Estimates That Matter	2021	VLDB	8.1282042e-05
3,269	Learned Cardinality Estimation: An In-depth Study	2022	SIGMOD	7.3026051e-05
3,670	The LDBC Social Network Benchmark: Business Intelligence Workload	2023	VLDB	6.8557811e-05
3,750	DIAMetrics: Benchmarking Query Engines at Scale	2020	VLDB	6.7864305e-05
3,924	A Unified Deep Model of Learning from both Data and Queries for Cardinality Estimation	2021	SIGMOD	6.6227223e-05
4,416	Don't Hold My Data Hostage - A Case For Client Protocol Redesign	2017	VLDB	6.1963721e-05
4,466	Robust Join Processing with Diamond Hardened Joins	2024	VLDB	6.1545841e-05
5,639	Analyzing the Impact of Cardinality Estimation on Execution Plans in Microsoft SQL Server	2023	VLDB	5.3972261e-05
5,772	Predicate Transfer: Efficient Pre-Filtering on Multi-Join Queries	2024	CIDR	5.3313794e-05
5,931	FASTgres: Making Learned Query Optimizer Hinting Effective	2023	VLDB	5.2632167e-05
5,978	SafeBound: A Practical System for Generating Cardinality Bounds	2023	SIGMOD	5.2424396e-05
6,683	Adaptive and Robust Query Execution for Lakehouses at Scale	2024	VLDB	4.9593505e-05
6,967	LpBound: Pessimistic Cardinality Estimation using ℓp-Norms of Degree Sequences	2025	SIGMOD	4.875312e-05
7,011	Simple Adaptive Query Processing vs. Learned Query Optimizers: Observations and Analysis	2023	VLDB	4.8583284e-05
7,122	Debunking the Myth of Join Ordering: Toward Robust SQL Analytics	2025	SIGMOD	4.8199209e-05
7,887	SQLStorm: Taking Database Benchmarking into the LLM Era	2025	VLDB	4.6218382e-05
8,035	Instance-Optimal Acyclic Join Processing Without Regret: Engineering the Yannakakis Algorithm in Column Stores	2025	VLDB	4.5967078e-05
8,777	Accelerate Distributed Joins with Predicate Transfer	2025	SIGMOD	4.4492064e-05
9,191	POLAR: Adaptive and Non-invasive Join Order Selection via Plans of Least Resistance	2024	VLDB	4.3738237e-05

Semantically Similar Papers

Overall Rank	Paper	Year	Venue	Pagerank
454	An Overview of Query Optimization in Relational Systems	1998	PODS	0.00022796106
6,687	How Good are Learned Cost Models, Really? Insights from Query Optimization Tasks	2025	SIGMOD	4.957987e-05
3,402	Query Optimizers: Time to Rethink the Contract?	2009	SIGMOD	7.134261e-05
8,193	On the Calculation of Optimality Ranges for Relational Query Execution Plans	2018	SIGMOD	4.5575291e-05
1,699	Are We Ready For Learned Cardinality Estimation?	2021	VLDB	0.00010848882
680	Towards a Robust Query Optimizer: A Principled and Practical Approach	2005	SIGMOD	0.00018193263
9,662	Efficient Query Re-optimization with Judicious Subquery Selections	2023	SIGMOD	4.3056334e-05
1,756	Sampling-Based Query Re-Optimization	2016	SIGMOD	0.00010659753
1,638	Cardinality Estimation in DBMS: A Comprehensive Benchmark Evaluation	2022	VLDB	0.00011050093
71	How Good Are Query Optimizers, Really?	2016	VLDB	0.00059446482