A DTD-DEPENDENT XML DATA MANAGEMENT SYSTEM: AN OBJECT-RELATION APPROACH

摘要

As the number of XML documents increases, a DBMS is becoming an essential part to store and retrieve the XML documents in an efficient and elaborate way. Although relational DBMSs are widely used for this purpose, they suffer from the model mismatch between graph structure of the XML documents and flat table structure of the relational databases. To overcome this problem, we propose an XML data management system called XING on top of an object-relational DBMS (ORDBMS). Since ORDBMSs support a graph structure with multi-valued attributes and object references, it is simple and natural to map the XML documents into the database. For efficient storage of huge XML documents, we devised XING-Tree which requires less memory space (about 20%) than that of the conventional DOM-Tree. Experiments show that our approach is superior to the one using conventional relational databases in the aspects of the space requirements (both in memory and disk) and query evaluation time.