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W3C's XQuery Language Standard

Posted by Dave Stodder and Ben Dupont on January 19, 2007

Tags: Ben Dupont,  DBMS,  David Stodder,  RDBMS,  SQL,  XML,  XML Query,  XML processing,  XQuery,  XQuery 1.0,  database management,  databases,  pending,  standard,  Database Technology and Applications,  Other,  Servers & Storage,  W3C,  XML

Channel: Other, Servers & Storage

The W3C's XQuery language standard is a catalyst for dramatic changes in database management; it will let businesses evolve relational systems to access, analyze and manage a wider range of data and information. Sponsors of the W3C's XQuery include DataDirect Technologies (a division of Progress Software), IBM, Microsoft and Oracle. Information architects must make careful choices about how to deploy XQuery and when to adopt XML schemas so that existing relational systems are not thrown into chaos. And while XQuery is still immature, it should have a major impact on gaining value from XML data.

The W3C's Xquery 1.0 moved to Proposed Recommendation status in November, bringing the prospect of a SQL-like approach to XML data querying one step closer to official sanction.

As happens with evolving standards, support for XQuery is making its way into mainstream products. IBM's DB2 version 9, for example, implements XQuery as part of its hybrid server. And Oracle gives database developers a choice of embedding XML inside SQL queries or employing the XQuery standard. Such developments represent an important change in the potential value of XML data.

XQuery essentially enables relational vendors to bring XML processing deeper into their database engines. The relational DBMS can then build XML indexes for optimizers to use, so the system can perform queries against XML data with the same efficiency as SQL. XQuery is also important for tiered architectures; database and middleware vendors can employ XQuery to access XML or SQL data from multiple, heterogeneous sources.

But XQuery is immature; it offers read-only access to XML data, though updating and other functions will be added later. And XQuery is not at all ready to support analytics and BI (business intelligence), unlike SQL.