Research On Extensions To RDBMS To Support XML Storage And Operations

XML has been widely used in all areas of Web applications. Due to the large amount of XML data in use, researchers in this field are paying more and more attention to increasing the efficiency of XML storage and operations. Since databases are able to store, operate and manage data effectively and efficiently, and after several decades of research Relational Database Management Systems (RDBMS) has grown into maturity, researchers begin to investigate implementing XML storage and operations on base of RDBMSs. Although many relational databases have their own solutions to support XML, there is no unified one applicable for all. Moreover, since no existing solution has eliminated the gap between XML and relational structures, this brings up the difficulties for storing and operating XML with relational DBs. In particular, few RDBMSs support XPATH.A general solution to make XML stored in relational DBs efficiently is proposed. Because XPATH is also supported, XML stored in relational DBs can be queried and operated efficiently as well.The proposed solution maps XML structures to relational ones by the use of XML Schemas, and this makes redundancy no longer be a problem compared with getting structures from detailed XML documents. This solution also separates data nodes and non-data nodes in XMLs, only stores data from data nodes while keeping non-data ones in XML structure. Therefore structures and data are separated, improving storage efficiency. At the same time, getting structures from XML Schemas also makes it easier to query data via XPATH and more efficiently than from XML documents directly. XPATH is taken as a general interface to query and operate XMLs stored in relational DBs. Because of the effieient storage structures, queries and operations via XPATH will be also efficient.