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A unified constraint model for XML

Research output: Contribution to journalArticle

Original languageEnglish
Pages (from-to)489-505
Number of pages17
JournalComputer Networks
Issue number5
Publication statusPublished - 2002


Integrity constraints are an essential part of modern schema definition languages. They are useful for semantic specification, update consistency control, query optimization, etc. In this paper, we propose UCM, a model of integrity constraints for XML that is both simple and expressive. Because it relies on a single notion of keys and foreign keys, the UCM model is easy to use and makes formal reasoning possible. Because it relies on a powerful type system, the UCM model is expressive, capturing in a single framework the constraints found in relational databases, object-oriented schemas and XML document type definitions. We study the problem of consistency of UCM constraints, the interaction between constraints and subtyping, and algorithms for implementing these constraints.

ID: 3969118