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: 2911
Venue: SIGMOD
Year: 1996
Pagerank: 0.00046301137
Overall Rank: 115 | 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
47	Data Integration: A Theoretical Perspective	2002	PODS	0.00069691761
61	DataGuides: Enabling Query Formulation and Optimization in Semistructured Databases	1997	VLDB	0.00064281097
153	Relational Databases for Querying XML Documents: Limitations and Opportunities	1999	VLDB	0.00040759404
206	Storing Semistructured Data with STORED	1999	SIGMOD	0.00034583517
227	Efficient Filtering of XML Documents for Selective Dissemination of Information	2000	VLDB	0.0003240219
276	Regular Path Queries with Constraints	1997	PODS	0.00029365217
295	Using Schema Matching to Simplify Heterogeneous Data Translation	1998	VLDB	0.00028645757
414	A Fast Index for Semistructured Data	2001	VLDB	0.00023801668
489	Your Mediators Need Data Conversion!	1998	SIGMOD	0.00021989648
504	Query Optimization for XML	1999	VLDB	0.00021513261
808	Query Containment for Conjunctive Queries With Regular Expressions	1998	PODS	0.000164132
864	APEX: An Adaptive Path Index for XML Data	2002	SIGMOD	0.00015781693
880	DTD Inference for Views of XML Data	2000	PODS	0.00015642282
928	DTL’s DataSpot: Database Exploration Using Plain Language	1998	VLDB	0.00015236575
1,080	Catching the Boat with Strudel: Experiences with a Web-Site Management System	1998	SIGMOD	0.00014204122
1,163	Extracting Schema from Semistructured Data	1998	SIGMOD	0.00013572993
1,314	Semistructured Data	1997	PODS	0.00012618313
1,601	Formal Models of Web Queries	1997	PODS	0.00011197057
1,658	Querying Network Directories	1999	SIGMOD	0.00010970782
1,667	Query Decomposition and View Maintenance for Query Languages for Unstructured Data	1996	VLDB	0.00010947593
1,900	Type Inference for Queries on Semistructured Data (Extended Abstract)	1999	PODS	0.00010168127
1,922	Cut and Paste	1997	PODS	0.00010084845
1,959	Deciding Containment for Queries with Complex Objects (Extended Abstract)	1997	PODS	9.958725e-05
2,210	To Weave the Web	1997	VLDB	9.2875159e-05
2,345	Rewriting of Regular Expressions and Regular Path Queries	1999	PODS	8.9933611e-05
2,393	STRUDEL: A Web-site Management System	1997	SIGMOD	8.8931317e-05
2,397	Query Rewriting for Semistructured Data	1999	SIGMOD	8.8888995e-05
3,114	Structure and Value Synopses for XML Data Graphs	2002	VLDB	7.5419224e-05
3,262	Path Constraints on Semistructured and Structured Data	1998	PODS	7.3081091e-05
3,659	The Complexity of Evaluating Path Expressions in SPARQL	2012	PODS	6.8684407e-05
3,683	Queries with Incomplete Answers over Semistructured Data	1999	PODS	6.84255e-05
3,718	Colorful XML: One Hierarchy Isn't Enough	2004	SIGMOD	6.8148882e-05
3,852	The Expressivity of XPath with Transitive Closure*	2006	PODS	6.6993728e-05
4,014	A Web Odyssey: from Codd to XML	2001	PODS	6.5300582e-05
4,276	Query Planning for Evaluating SPARQL Property Paths	2016	SIGMOD	6.2884651e-05
4,552	View-Based Query Containment	2003	PODS	6.0856349e-05
4,978	Constraint Satisfaction and Database Theory: a Tutorial	2000	PODS	5.7833452e-05
5,267	On the Optimization of Recursive Relational Queries: Application to Graph Queries	2020	SIGMOD	5.5930569e-05
5,727	Query Processing under GLAV Mappings for Relational and Graph Databases	2013	VLDB	5.3501787e-05
5,934	Capturing and Querying Multiple Aspects of Semistructured Data	1999	VLDB	5.2617479e-05
6,293	Containment of Nested XML Queries	2004	VLDB	5.1206121e-05
6,756	Views in a Large Scale XML Repository	2001	VLDB	4.9340552e-05
6,956	Computational Aspects of Resilient Data Extraction from Semistructured Sources	2000	PODS	4.8811374e-05
7,857	On Views and XML	1999	PODS	4.6302986e-05
9,669	Type inference in the polymorphic relational algebra	1999	PODS	4.3033855e-05
11,975	Does Query Evaluation Tractability Help Query Containment?	2014	PODS	4.1905499e-05
12,672	Querying Websites Using Compact Skeletons	2001	PODS	4.1905499e-05
12,714	Using LDAP Directory Caches	1999	PODS	4.1905499e-05
12,747	DTL's DataSpot: Database Exploration as Easy as Browsing the Web...	1998	SIGMOD	4.1905499e-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	0.00030241337
272	Querying Object-Oriented Databases	1992	SIGMOD	0.0002942487
669	F-Logic: A Higher-Order Language for Reasoning about Objects, Inheritance, and Scheme	1989	SIGMOD	0.00018413233
3,744	A Data Transformation System for Biological Data Sources	1995	VLDB	6.7938433e-05

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3,115	Processing Queries on Tree-Structured Data Efficiently	2006	PODS	7.5414053e-05
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9,536	Graph Data Models, Query Languages and Programming Paradigms	2018	VLDB	4.3225428e-05
460	Graphs-at-a-time: Query Language and Access Methods for Graph Databases	2008	SIGMOD	0.00022679846
12,856	Investigation of Algebraic Query Optimisation for Database Programming Languages	1994	VLDB	4.1905499e-05
144	Optimization of Nonrecursive Queries	1986	VLDB	0.00041430126
102	Of Nests and Trees: A Unified Approach to Processing Queries That Contain Nested Subqueries, Aggregates, and Quantifiers	1987	VLDB	0.00049592627
2,109	A Recursive Algebra and Query Optimization for Nested Relations	1989	SIGMOD	9.5283567e-05
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