A Query Language and Optimization Techniques for Unstructured Data

Summary: UnQL: a query language for rooted, edge-labeled graphs modeling unstructured data; relational data are representable as fixed-depth trees. Supports arbitrarily deep data and cycles beyond path expressions; efficient evaluation uses vertical optimization with relational-style optimizers on the horizontal dimension. (summarized by gpt-5-nano on Feb 09 2026)

Paper ID: 2910
Venue: SIGMOD
Year: 1996
Pagerank: 0.00046339735
Overall Rank: 114 | 99.21%
DOI: -

Incoming Non-self Citations Over Time

Authors

Incoming Citations (Sorted by Pagerank)

Showing 49 of 49 citing papers.

Rank	Citing Paper	Year	Venue	Pagerank
48	Data Integration: A Theoretical Perspective	2002	PODS	0.00069720859
61	DataGuides: Enabling Query Formulation and Optimization in Semistructured Databases	1997	VLDB	0.00064329285
153	Relational Databases for Querying XML Documents: Limitations and Opportunities	1999	VLDB	0.00040784455
207	Storing Semistructured Data with STORED	1999	SIGMOD	0.00034611968
226	Efficient Filtering of XML Documents for Selective Dissemination of Information	2000	VLDB	0.00032431532
274	Regular Path Queries with Constraints	1997	PODS	0.00029390022
294	Using Schema Matching to Simplify Heterogeneous Data Translation	1998	VLDB	0.00028669519
415	A Fast Index for Semistructured Data	2001	VLDB	0.00023814619
491	Your Mediators Need Data Conversion!	1998	SIGMOD	0.00022011503
501	Query Optimization for XML	1999	VLDB	0.00021530411
810	Query Containment for Conjunctive Queries With Regular Expressions	1998	PODS	0.00016428374
869	APEX: An Adaptive Path Index for XML Data	2002	SIGMOD	0.00015788339
882	DTD Inference for Views of XML Data	2000	PODS	0.00015657456
927	DTL’s DataSpot: Database Exploration Using Plain Language	1998	VLDB	0.00015248642
1,081	Catching the Boat with Strudel: Experiences with a Web-Site Management System	1998	SIGMOD	0.00014216794
1,163	Extracting Schema from Semistructured Data	1998	SIGMOD	0.00013577466
1,314	Semistructured Data	1997	PODS	0.0001263326
1,599	Formal Models of Web Queries	1997	PODS	0.00011202032
1,662	Querying Network Directories	1999	SIGMOD	0.00010977682
1,669	Query Decomposition and View Maintenance for Query Languages for Unstructured Data	1996	VLDB	0.00010955767
1,897	Type Inference for Queries on Semistructured Data (Extended Abstract)	1999	PODS	0.00010178006
1,919	Cut and Paste	1997	PODS	0.00010094755
1,952	Deciding Containment for Queries with Complex Objects (Extended Abstract)	1997	PODS	9.9677831e-05
2,204	To Weave the Web	1997	VLDB	9.2970809e-05
2,342	Rewriting of Regular Expressions and Regular Path Queries	1999	PODS	9.0015589e-05
2,392	STRUDEL: A Web-site Management System	1997	SIGMOD	8.9020636e-05
2,399	Query Rewriting for Semistructured Data	1999	SIGMOD	8.8973689e-05
3,113	Structure and Value Synopses for XML Data Graphs	2002	VLDB	7.5469926e-05
3,257	Path Constraints on Semistructured and Structured Data	1998	PODS	7.3151681e-05
3,652	The Complexity of Evaluating Path Expressions in SPARQL	2012	PODS	6.875313e-05
3,681	Queries with Incomplete Answers over Semistructured Data	1999	PODS	6.8492288e-05
3,716	Colorful XML: One Hierarchy Isn't Enough	2004	SIGMOD	6.8214504e-05
3,851	The Expressivity of XPath with Transitive Closure*	2006	PODS	6.7057867e-05
4,010	A Web Odyssey: from Codd to XML	2001	PODS	6.5351699e-05
4,280	Query Planning for Evaluating SPARQL Property Paths	2016	SIGMOD	6.2948356e-05
4,553	View-Based Query Containment	2003	PODS	6.091702e-05
4,977	Constraint Satisfaction and Database Theory: a Tutorial	2000	PODS	5.7881576e-05
5,259	On the Optimization of Recursive Relational Queries: Application to Graph Queries	2020	SIGMOD	5.5984356e-05
5,717	Query Processing under GLAV Mappings for Relational and Graph Databases	2013	VLDB	5.3553228e-05
5,933	Capturing and Querying Multiple Aspects of Semistructured Data	1999	VLDB	5.2668503e-05
6,294	Containment of Nested XML Queries	2004	VLDB	5.1255418e-05
6,752	Views in a Large Scale XML Repository	2001	VLDB	4.9388171e-05
6,958	Computational Aspects of Resilient Data Extraction from Semistructured Sources	2000	PODS	4.8857878e-05
7,856	On Views and XML	1999	PODS	4.6347452e-05
9,669	Type inference in the polymorphic relational algebra	1999	PODS	4.3074872e-05
11,967	Does Query Evaluation Tractability Help Query Containment?	2014	PODS	4.1945683e-05
12,663	Querying Websites Using Compact Skeletons	2001	PODS	4.1945683e-05
12,705	Using LDAP Directory Caches	1999	PODS	4.1945683e-05
12,738	DTL's DataSpot: Database Exploration as Easy as Browsing the Web...	1998	SIGMOD	4.1945683e-05

Outgoing Citations (Sorted by Pagerank)

Showing 4 of 4 cited papers.

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

Rank	Cited Paper	Year	Venue	Pagerank
256	GraphLog: a Visual Formalism for Real Life Recursion	1990	PODS	0.00030259041
271	Querying Object-Oriented Databases	1992	SIGMOD	0.00029452935
669	F-Logic: A Higher-Order Language for Reasoning about Objects, Inheritance, and Scheme	1989	SIGMOD	0.00018430212
3,769	A Data Transformation System for Biological Data Sources	1995	VLDB	6.7782158e-05

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