IN-PLACE EVOLUTION OF XML SCHEMAS IN DATABASES

摘要

A method and system for the in-place evolution of XML schemas is disclosed. To automatically evolve an existing XML schema, a schema evolver receives both an existing XML schema and an XML document as input. The XML document indicates changes to be made to the existing XML schema. Based on the existing XML schema and the XML document, the schema evolver evolves the existing XML schema into a new XML schema that incorporates the changes indicated in the XML document. According to one aspect, the schema evolver generates one or more SQL statements based on the new XML schema. The SQL statements, when executed by a database server, cause the database server to evolve database structures that were based on the formerly existing XML schema so that the database structures conform to the new XML schema. This is accomplished "in place," without copying the data in the database structures.