A new normal form for nested relations
ACM Transactions on Database Systems (TODS)
Extended algebra and calculus for nested relational databases
ACM Transactions on Database Systems (TODS)
A normal form for precisely characterizing redundancy in nested relations
ACM Transactions on Database Systems (TODS)
A simplied universal relation assumption and its properties
ACM Transactions on Database Systems (TODS)
A characterization of globally consistent databases and their correct access paths
ACM Transactions on Database Systems (TODS)
On the Desirability of Acyclic Database Schemes
Journal of the ACM (JACM)
A Guided Tour of Relational Databases and Beyond
A Guided Tour of Relational Databases and Beyond
Developing XML Documents with Guaranteed ``Good'' Properties
ER '01 Proceedings of the 20th International Conference on Conceptual Modeling: Conceptual Modeling
The VLDB Journal — The International Journal on Very Large Data Bases
Anatomy of a native XML base management system
The VLDB Journal — The International Journal on Very Large Data Bases
A normal form for XML documents
ACM Transactions on Database Systems (TODS)
Strong functional dependencies and their application to normal forms in XML
ACM Transactions on Database Systems (TODS)
Redundancy, dependencies and normal forms for XML databases
ADC '05 Proceedings of the 16th Australasian database conference - Volume 39
Removing XML data redundancies using functional and equality-generating dependencies
ADC '05 Proceedings of the 16th Australasian database conference - Volume 39
Native XML support in DB2 universal database
VLDB '05 Proceedings of the 31st international conference on Very large data bases
Theory of Relational Databases
Theory of Relational Databases
Generating Compact Redundancy-Free XML Documents from Conceptual-Model Hypergraphs
IEEE Transactions on Knowledge and Data Engineering
XML design for relational storage
Proceedings of the 16th international conference on World Wide Web
Efficiently Querying Large XML Data Repositories: A Survey
IEEE Transactions on Knowledge and Data Engineering
RRXS: redundancy reducing XML storage in relations
VLDB '03 Proceedings of the 29th international conference on Very large data bases - Volume 29
XML schema refinement through redundancy detection and normalization
The VLDB Journal — The International Journal on Very Large Data Bases
XSym'07 Proceedings of the 5th international conference on Database and XML Technologies
Design non-recursive and redundant-free XML conceptual schema with hypergraph
DASFAA'11 Proceedings of the 16th international conference on Database systems for advanced applications
When conceptual model meets grammar: A dual approach to XML data modeling
Data & Knowledge Engineering
On an Enhancement of XML Applied for Mobile E-Commerce
Journal of Electronic Commerce in Organizations
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Given a hypergraph and a set of embedded functional dependencies, we investigate the problem of determining the conditions under which we can efficiently generate redundancy-free XML storage structures with as few scheme trees as possible. Redundancy-free XML structures guarantee both economy in storage space and the absence of update anomalies, and having the least number of scheme trees requires the fewest number of joins to navigate among the data elements. We know that the general problem is intractable. The problem may still be intractable even when the hypergraph is acyclic and each hyperedge is in Boyce-Codd normal form (BCNF). As we show here, however, given an acyclic hypergraph with each hyperedge in BCNF, a polynomial-time algorithm exists that generates a largest possible redundancy-free XML storage structure. Successively generating largest possible scheme trees from among hyperedges not already included in generated scheme trees constitutes a reasonable heuristic for finding the fewest possible scheme trees. For many practical cases, this heuristic finds the set of redundancy-free XML storage structures with the fewest number of scheme trees. In addition to a correctness proof and a complexity analysis showing that the algorithm is polynomial, we also give experimental results over randomly generated but appropriately constrained hypergraphs showing empirically that the algorithm is indeed polynomial.