Constraints for semistructured data and XML

Xml and Semistructured Data

Semistructured Data and XML

Constraints for Semistructured Data

A taxonomy of constraints for semistructured data models is presented. Several existing classes of constrains defined for different database models, such as relational and objectoriented, are analyzed in the context of semistructured data model. To capture dynamic aspects of consistency, data validity constraints are introduced. The most important subclass of data validity constraints, temporal...

Pattern Queries for XML and Semistructured Data

Query and transformation languages developed since the mid 90es for XML and semistructured data – e.g. XQuery, the precursors of XQuery, and XSLT – built upon a path-oriented node selection: A node in a data item is specified in terms of a root-to-node path in the manner of the file selection languages of operating systems. Constructs from regular expressions such as ∗, +, ?, and “wildcards” gi...

Path constraints in semistructured data

We consider semistructured data as multi rooted edge-labeled directed graphs, and path inclusion constraints on these graphs. A path inclusion constraint p q is satisfied by a semistructured data if any node reached by the regular query p is also reached by the regular query q. In this paper, two problems are mainly studied: the implication problem and the problem of the existence of a finite e...