July 13, 2010

DB2 10 pureXML

The introduction of pureXML in DB2 9 for z/OS gave administrators a way to store well-formed XML documents in their hierarchical form and retrieve all or portions of these documents. Prior to DB2 9, storing XML was a chore -- the available options were to either shred the documents and archive the XML data in relational tables as relational columns, or store them in a LOB, which posed its own performance and processing problems. DB2 9 users quickly grew to appreciate the labor savings, shortened development cycles and greater flexibility that pureXML offers.

DB2 9 pureXML offered these additional benefits:

•    New storage techniques for efficient management of XML documents.
•    New index technology to speed the process of accessing XML documents.
•    New query language support for XQuery, a new graphical query build for XQuery, and new query optimization techniques.
•    Support for validating XML data based on user-supplied schemas.

DB2 10 will include a second release of pureXML. This updated version is designed to provide numerous performance and usability improvements such as automatic XML schema validation. With this new function, you won't have to specify XML schema for validation -- DB2 will search and find a schema. DB2 also supports multiple schema versions, so existing older documents won't need to be changed.

DB2 10 pureXML is also expected to include:

•    A binary XML exchange format that's designed to improve performance.
•    XML multi-versioning, which is designed to improve concurrency and performance.
•    Support UPDATE on sub-parts of XML documents.
•    Enhanced XML support in stored procedures, UDF and triggers.
•    XML index matching with date and timestamp.
•    CHECK XML and CHECK DATA utilities. The latter will verify the consistency of XML documents stored in a separate XML table space.

If you're just getting started with pureXML, be sure to check out these IBM Redbooks: "DB2 9 pureXML Overview and Fast Start" and "DB2 9 pureXML Guide."