Table of Contents

Editorial: Self Describing by Steve Jones

Introduction to XML by Wayne Fillis An introduction to what XML really is and how it fits into a DBA's world.
	XML, Worth the Upgrade? by Jon Winer and Kendal Van Dyke A comparison of XML features in SQL Server 2005 and 2000 with an eye towards the advantages of upgrading existing applications.
Opening HTTP Endpoints by Chris Shaw and P. Lance Sheldon A practical look at HTTP endpoints, one of the foundations of SQL Server 2005 communictions using XML documents.
	SQL Server 2005 Becomes a Hub in Your Service-Oriented Ecosystem by Tom Fuller A look at how SQL Server 2005 fits into an SOA architecture from the perspective of using XML and web services.
Recusive Hierarchies to XML by Christian Wade A practical example of how XML can handle a hierarchial structure.
	Demystifying SQL Server Notification Services by Andrei Kossoroukov Alerts and other types of notifications are the basis on which Notification Services was developed. This article examines just how useful this subsystem can be with a practical example.
XML Schema binding by Wayne Fillis Validating an XML document is made easy by binding documents to a predefined schema. This article examines just how this works.
	Using XML to Solve Relational Problems by Denis Ruckebusch A practical look at just how XML can be used to handle a variety of relational database problems.
How To Make The Impossible Possible by Peter Ward

One of the first real benefits that I heard about with XML over a decade ago was the self-describing nature of this data format. By using tags that both delimited data as well as described it, we could easily add or subtract from the formats without forcing major changes to import/export programs. Since I was knee deep in an EDI project at the time with it’s very precise and rigid data formats, XML seemed to be a wonderful relief and I looked forward to it being implemented in many applications in the future.

This was just as SQL Server 7 was coming to market and it wasn’t long before we saw a variety of XML features added to SQL Server, including native web services in SQL Server 2005. The XML capabilities of this latest release are far beyond anything I dreamed about in the late 90s as I slogged through my EDI work and became more excited with each new piece of news on XML.

However I haven’t seen the widespread adoption of XML that I expected. In fact, most of the applications I’ve worked on in the last decade haven’t used XML at all. It’s not that the technology wouldn’t have worked, but it wasn’t needed and the same types of techniques I’ve used for nearly two decades in applications worked well enough that we decided to stick with them.

However XML is growing in popularity and the many new features of SQL Server 2005 that take advantage of XML mean that the modern SQL Server DBA needs to be more familiar with XML and the implications of using it in the database. This issue is devoted to XML with a look at how you might incorporate XML into your environment. We start with Wayne Fillis’ basic look at what XML is since it’s not as pervasive a technology as many people would like. Wayne has also written an article looking at how XML schema binding is used.

From there we move on to an interesting examination of whether the XML features in SQL Server 2005 are worth the upgrade from SQL Server 2000. Jon Winer and Kendal Van Dyke make heavy use of XML in their jobs, so it’s a practical look at what has changed.

We also have a few practical articles on HTTP Endpoints, XML in an SOA architectural model, and how recursive hierarchies are handled with XML. These are practical articles from people actually using XML, and they should give you an idea of the capabilities of this technology. We also have a great one from Denis Ruckebush on using XML to solve relational problems.

Lastly we depart from XML slightly with a look at Notification Services, another great new subsystem in SQL Server 2005 that can greatly expand the capabilities of your applications.

I’m not a great XML fan, but I do see it becoming more popular if not pervasive throughout the computer world as more and more systems become interconnected. We hope you enjoy this issue and learn a few things about how XML might be used in your world.

Steve Jones