Flexible Modification of Relational Schema by X2RMap in Storing XML into Relations

Abstract

Among many attempts to effectively store and query massive quantity of XML data, one method using RDBMS is drawing attention. It is to create appropriate relational schema by using DTD and then divide and store the XML document according to the schema. XML query for data stored as above can be implemented by rewriting it into SQL. Among this series of processes, in fact, intermediate mapping concept becomes necessary due to the difference between DTD and relational schema. It can help a user to compose a XML query transparently from a virtual physical structure, a relational schema. So, though the relational schema is properly modified for query performance, it doesn’t have an effect on XML query. In this paper, we introduce some effective methods for flexible modification of relational schema using mapping structure, X2RMap.