Diag-Join: An Opportunistic Join Algorithm for 1:N Relationships

Summary: Diag-Join exploits time-of-creation clustering to enable an opportunistic join for 1:N relations. It outperforms block-wise nested-loop join, GRACE hash join, and index nested-loop join on clustered data and provides an analytical cost model. (summarized by gpt-5-nano on Feb 09 2026)

Paper ID: 8671
Venue: VLDB
Year: 1998
Pagerank: 5.8345497e-05
Overall Rank: 6,586 | 54.82%
DOI: -

Incoming Non-self Citations Over Time

Authors

1. Sven Helmer (University of Mannheim)
2. Till Westmann (University of Mannheim)
3. Guido Moerkotte (University of Mannheim)

BibTeX Citation

@article{helmer_vldb98,
        title = {{Diag-Join: An Opportunistic Join Algorithm for 1:N Relationships}},
        author = {Helmer, Sven and Westmann, Till and Moerkotte, Guido},
        journal = {PVLDB},
        series = {{VLDB} '98},
        year = {1998}
}

Incoming Citations (Sorted by Pagerank)

Showing 2 of 2 citing papers.

Rank	Citing Paper	Year	Venue	Pagerank
1,369	How Soccer Players Would do Stream Joins	2011	SIGMOD	0.0001099892
5,443	Generalized Hash Teams for Join and Group-by	1999	VLDB	6.2177595e-05

Outgoing Citations (Sorted by Pagerank)

Showing 12 of 12 cited papers.

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

Rank	Cited Paper	Year	Venue	Pagerank
7	Implementation Techniques For Main Memory Database Systems	1984	SIGMOD	0.00083340894
80	Hashing Methods and Relational Algebra Operations	1984	VLDB	0.00036536643
152	Multiprocessor Hash-Based Join Algorithms	1985	VLDB	0.00029038365
652	An Overview of The System Software of A Parallel Relational Database Machine GRACE	1986	VLDB	0.00015304915
844	Hash-Partitioned Join Method Using Dynamic Destaging Strategy	1988	VLDB	0.00013664056
904	Tradeoffs in Processing Complex Join Queries via Hashing in Multiprocessor Database Machines	1990	VLDB	0.00013319798
1,299	A Low Communication Sort Algorithm for a Parallel Database Machine	1989	VLDB	0.00011258763
2,230	The Effect of Bucket Size Tuning in the Dynamic Hybrid GRACE Hash Join Method	1989	VLDB	8.9026958e-05
3,842	FastSort: A Distributed Single-Input Single-Output External Sort	1990	SIGMOD	7.0803078e-05
4,042	Join Index Hierarchies for Supporting Efficient Navigations in Object-Oriented Databases	1994	VLDB	6.9407646e-05
6,448	Indexing Multiple Sets	1994	VLDB	5.8757981e-05
7,705	A Study of Sort Algorithms for Multiprocessor Database Machines	1986	VLDB	5.5642777e-05

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1	6,172	On Spatially Partitioned Temporal Join	1994	VLDB
2	1,022	A Scalable, Predictable Join Operator for Highly Concurrent Data Warehouses	2009	VLDB
3	1,479	Computing Joins Of Relations	1975	SIGMOD
4	844	Hash-Partitioned Join Method Using Dynamic Destaging Strategy	1988	VLDB
5	8,235	Computing Complex Temporal Join Queries Efficiently	2022	SIGMOD
6	4,630	Efficient Join Synopsis Maintenance for Data Warehouse	2020	SIGMOD
7	3,453	On Join Sampling and the Hardness of Combinatorial Output-Sensitive Join Algorithms	2023	PODS
8	3,617	Scalable Computation of Acyclic Joins (Extended Abstract)	2006	PODS
9	3,977	Event-Join Optimization in Temporal Relational Databases	1989	VLDB
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