Paper Info
Title
Assisting XML Schema Evolution that Preserves Validity
Abstract
We consider the problem of XML schema evolution preserving t he va- lidity of existing documents related to the original schema . The aim of such schema evolution is to fit new needs without revalidating all e xisting valid XML documents. We propose an approach to assist users to specify schema updates that have no impact on existing document validity. An XML sch ema is modeled as a set of regular expressions, each constraining the conte nt model of XML ele- ments. Given the user needs, we work on Glushkov graphs represe nting regular expressions E in the schema. By this way, we get straightforwardly the right places inE that may be changed while preserving validity. The schema evolution problem deals with the update of a schema when it no longer meets the needs of the user. The goal of schema evolution research is to allow schemas to change while maintaining access to the existing data. Indeed, the evolution can be conservative or non-conservative. In the first case, all documents that were valid wrt the old schema are valid wrt the new one. In the second case, documents valid for the original schema are no more guaranteed to meet the new schema. The non-conservative schema evolution may be problematic since it is necessary to validate all documents against the new schema and, if they are not valid, they should be adapted to it. The document adaption process can provoke data loss since it may be necessary to delete tags (and their information) from it.
Year
Venue
Keywords
2007
SBBD
xml document,xml schema,regular expression
Field
DocType
Citations 
XML Schema (W3C),Information retrieval,Star schema,XML validation,Computer science,Document Structure Description,RELAX NG,XML schema,Schema evolution,Database,XML Schema Editor
Conference
3
PageRank 
References 
Authors
0.37
15
2
Name
Order
Citations
PageRank
beatrice bouchou19110.71
Denio Duarte2486.45