On the Intersection of XPath Expressions

— XPath is a common language for selecting nodes in an XML document. XPath uses so called path expressions which describe a navigation path through semistructured data. In the last years some of the characteristics of XPath have been discussed. Examples include the containment of two XPath expressions p and p (p ⊆ p ). To the best of our knowledge the intersection of two XPath expressions (p ∩ p ) has not been treated yet. The intersection of p and p is the set that contains all XML nodes that are selected both by p and p . In the context of indexes in XML databases the emptiness of the intersection of p and p is a major issue when updating the index. In order to keep the index consistent to the indexed data, it has to be detected if an index that is defined upon p is affected by a modifying database operation with the path expression p . In this paper we introduce the intersection problem for XPath and give a motivation for its relevance. We present an efficient intersection a...

• Type: Conference
• Year: 2005
• Where: IDEAS
• Authors: Beda Christoph Hammerschmidt, Martin Kempa, Volker Linnemann
• Keywords: Database, IDEAS 2005, Intersection Problem, XPath, XPath Expressions