A Translation Algorithm for Effective RDB-to-XML Schema Conversion Considering Referential Integrity Information

In this paper, we propose a new relational schema (R-schema) to XML Schema translation algorithm that analyzes the cardinality between data values and patterns of user queries to resolve the implicit referential integrity issue. Many translation methods have been developed taking into account structural and/or semantic aspects. However, earlier methods have considered only the explicit referential integrity specified by the R-schema during translation or partially reflect the implicit referential integrity. It causes several problems such as incorrect translations, abnormal relational model transitions, and so on. In addition, many conventional translation algorithms support XML document type declaration (DTD) as the final translation result. However, it is insufficient to exactly represent the information of the R-schema. The VQT algorithm analyzes the value cardinality and user query patterns and extracts the implicit referential integrities by using the cardinality property of foreign key constraints between columns and the equi-join characteristic in user queries. The VQT algorithm can apply the extracted implied referential integrity relation information to the R-schema and create an XML Schema as the final result. Therefore, the VQT algorithm prevents the R-schema from incorrectly converting into the XML Schema, and it richly and powerfully represents all the information in the R-schema by creating ail XML Schema as the translation result on behalf of the XML DTD.