Study Of The XML Storage And Query Technology In Relational Database

XML(eXtensible Markup Language) has established the position in the Internet. Research and application of the XML is emerging and rapidly developing in the Internet era, and XML data management technology is becoming one of most popular research areas in the database academic circle.Since the relational database technology have already been mature,and XML data is stored by the relational database technology in the most system,the research of XML data management based on relational database is got widespread attention.This paper analyzed the current domestic and foreign research situation about XML data managerial technique based on the relational database,and researched and studied on the XML relational storagement, the DTD's absolute consistency and the technology of XML indix and so on. Specifically, the main ones are as follows:First,the paper introduced a new XML data storage method. This method encoded XML documents and DTD documents respectively, and stored the path information of the element node as a string in the DTD coded group,and accelerated path query efficiency.Second,the paper introduced an algorithm for checking and correcting absolute consistency of DTDs. This algorithm, with linear time complexity,could judged absolute consistency of DTDs only by DTD path information.It realized checking and correcting absolute consistency of DTDs, and solved the problem that there be unestablished-consistency sub-structure in the established-consistency DTD.Third,the paper gave a method which created index on the DTD and XML documents respectively based on the storage method of the XML data. At the same time, the paper gave a query program which combinated path-method and the phase structure of connections.It first judged the condition match path and the goal match path according to XML path which to be queried and conducted matching DTD structure.Then it carried on query processing in the XML documents according to the different situations. Because this query approach was first carried on DTD whose scale was smaller than XML,it speeded up the query.At the same time,it could give a fast feedback to the invalid path which was gived by the user.Last,a prototype system was designed and implemented based on the proposed storage, index and query method.The system had a good performance in storing and quering XML documents,and it had an ideal effect on storing and quering general XML documents in relation databases.