Coalescing in Temporal Databases

Summary: Coalescing is a temporal unary operator; the paper shows how to prune semantically unnecessary coalescing. It surveys DBMS algorithms (nested-loop, sorting, partitioning) and SQL approaches, with a study showing feasibility but nontrivial cost. (summarized by gpt-5-nano on Feb 09 2026)

Paper ID: he1516e0d846ee464
Venue: VLDB
Year: 1996
Pagerank: 7.0702677e-05
Overall Rank: 3,724 | 74.97%
DOI: -

Incoming Non-self Citations Over Time

Authors

1. Michael H. Böhlen (Aalborg University)
2. Richard T. Snodgrass (University of Arizona)
3. Michael D. Soo (University of South Florida)

BibTeX Citation

@article{bohlen_vldb96,
        title = {{Coalescing in Temporal Databases}},
        author = {Böhlen, Michael H. and Snodgrass, Richard T. and Soo, Michael D.},
        journal = {PVLDB},
        series = {{VLDB} '96},
        pages = {180},
        year = {1996}
}

Incoming Citations (Sorted by Pagerank)

Showing 8 of 8 citing papers.

Rank	Citing Paper	Year	Venue	Pagerank
4,561	Temporal Coalescing with Now, Granularity, and Incomplete Information	2003	SIGMOD	6.534151e-05
5,136	Temporal Slicing in the Evaluation of XML Queries	2003	VLDB	6.2585559e-05
6,497	Capturing and Querying Multiple Aspects of Semistructured Data	1999	VLDB	5.7653313e-05
6,794	Snapshot Semantics for Temporal Multiset Relations	2019	VLDB	5.6806763e-05
7,577	Scalable Architecture and Query Optimization for Transaction-time DBs with Evolving Schemas	2010	SIGMOD	5.4924978e-05
7,857	TIP: A Temporal Extension to Informix	2000	SIGMOD	5.4396702e-05
8,743	LIT: Lightning-fast In-memory Temporal Indexing	2024	SIGMOD	5.2882178e-05
9,062	Preference-aware Integration of Temporal Data	2015	VLDB	5.2288029e-05

Outgoing Citations (Sorted by Pagerank)

Showing 5 of 5 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	0.00081992507
125	Predicate Migration: Optimizing Queries with Expensive Predicates	1993	SIGMOD	0.00030470848
220	An Evaluation of Non-Equijoin Algorithms	1991	VLDB	0.00024344086
2,032	Practical Predicate Placement	1994	SIGMOD	9.1561026e-05
5,538	Temporal Query Processing and Optimization in Multiprocessor Database Machines	1992	VLDB	6.0918672e-05

Semantically Similar Papers

#	Overall Rank	Paper	Year	Venue
1	13,452	Temporal Relationships in Databases	1988	VLDB
2	1,514	Computing Joins Of Relations	1975	SIGMOD
3	6,426	Temporal Alignment	2012	SIGMOD
4	821	Query Execution Techniques for Caching Expensive Methods	1996	SIGMOD
5	6,287	On Spatially Partitioned Temporal Join	1994	VLDB
6	13,385	A Uniform Approach to Processing Temporal Queries	1992	VLDB
7	5,538	Temporal Query Processing and Optimization in Multiprocessor Database Machines	1992	VLDB
8	7,609	Computing Complex Temporal Join Queries Efficiently	2022	SIGMOD
9	4,063	Event-Join Optimization in Temporal Relational Databases	1989	VLDB
10	4,561	Temporal Coalescing with Now, Granularity, and Incomplete Information	2003	SIGMOD