What can be obtained through DB2 9 XML?

This article mainly describes what we all want to obtain through DB2 9 XML in actual operations? During the five years of development of pureXML and DB2 9 databases, IBM has thoroughly studied the nature of XML (XML is flexible and cumbersome ), five improvements are found.

IBM focuses on two performance factors: storage model and query optimization.

XML data is represented by a hierarchical tree structure that usually contains multiple layers and a large number of nodes. Therefore, this format is difficult to optimize and compile indexes. It also involves some form of compression. Therefore, XML queries may become very complex.

A common method for storing XML data is the character large object (CLOB ). Like a Binary Large Object (BLOB), CLOB is usually used as a whole for storage and is rarely pre-processed for indexing or query optimization. Another method is to "break down" XML data into columns of relational data. This method requires complex parsing techniques and usually uses a large amount of storage space.

DB2 pureXML stores XML data in a pre-Resolved hierarchical format that reflects the underlying nested structure of the data. This format supports compiling complex indexes and compressing data in physical storage. During query execution, pureXML converts XQuery and SQL/XML queries into a unified format optimized in many aspects (cross-language, query rewriting, optimized indexing, and cost. XML compression, query optimization, and the combination of relational and XML Processing (improved insertion and update Performance in DB2 9.5) improve the processing performance of the database. IBM's testing and real projects show that, compared with similar operations in DB2 V8 or other DBMS, the speed is increased by 10 to 20 times (see the "Joy of success" section in relevant content ).

More suitable for the DB2 9 XML Model

The performance characteristics of pureXML also include adaptability. Key Point: XML data does not replace relational data. For standard financial businesses, XML data is difficult to surpass relational databases, but RDBMS is difficult to process publications, such as the whole book, magazine, or journal. RDBMS is hard to process if the data in an application has a complex hierarchy or contains a large amount of unstructured information.

For example, life sciences organizations are converting many common data from various proprietary formats to XML. In some cases, for data that is difficult to store and extract in traditional RDBMS, the XML format provides an optimized data access path, which makes the XML database fundamentally superior in performance.

Xml dbms has another advantage: it can communicate directly with DB2 9 XML applications through Web services or other methods. Because XML is widely used on the Internet, the communication between applications is also widely used in XML format, so the entire communication chain (Application-message-database) it makes sense to use the XML format.

IBM pureXML has many significant technological innovations (68 new patents !), However, the true value of the IBM relationship/XML model lies in the performance it shows in mainstream enterprise applications.

The above content is an introduction to what we get through DB2 9 XML. I hope you will get something better.