Microsoft released SQL Server 2000 Notification Services on Monday, continuing to extend SQL Server's reach beyond traditional relational database functionality. When I first wrote about Notification Services 5 months ago, the beta version had just rolled out. So what is this newest component of the data-management and integration tools that now comes bundled with SQL Server?

Notification Services is a set of technologies for developing and deploying applications that generate and send personalized notifications to wired or wireless devices. Notification Services scans input events from a variety of sources, matches the events against a user's subscriptions, generates and formats personalized notifications, and delivers the notifications to the subscriber's preferred device. Notification Services grew out of joint development efforts with MSN, which is now using the component in production. MSN Mobile began seeing massive growth in its subscriber base and the events those subscribers wanted to receive notices about. MSN was adding server after server to handle the increasing load, creating a server farm that was quickly becoming expensive and unmanageable. Generating a notification event doesn't seem like a database problem at first glance. But when Microsoft looked at the MSN business need, it realized that matching event data to users' request for data is, at its core, a data issue. Notification Services now helps MSN provide more reliable event notification for subscribers and has let MSN reduce the number of servers handling notification events by more than a factor of 10.

You've probably built alert services before, and you might be thinking, "How hard is it to send someone an email? Do I really need to use a tool like Notification Services, or should I just build my own solution?" Creating your own solution might be reasonable if you're dealing with a few events, a few consumers, and one distribution channel—and you don't need to customize delivery based on intricate rules that users set up. Unfortunately, data integration becomes thorny as the number of events, consumers, and channels grows and the delivery rules become complex. We won't even consider the possibility of needing to scale your homegrown solution to hundreds of thousands or millions of users.

Microsoft is essentially a plumbing and platform company. And its biggest successes happen when it creates a platform that hides the nasty infrastructure and integration problems associated with technology, freeing developers to focus on business logic rather than technological plumbing. Notification Services provides the common plumbing necessary to build a robust event-capture and notification environment. I predict that many customers will find creative and practical ways to use this technology.

Senior Microsoft executives are touting Notification Services as a crucial piece in the .NET initiative to break the barriers of knowledge transfer to information consumers. And although Notification Services is important as an enabling technology, it's also important as a technology that helps extend SQL Server beyond the relational database engine. The trend to expand SQL Server's functional reach started several years ago, when Microsoft rolled out OLAP Services with SQL Server 7.0. SQL Server 2000 added data-mining capabilities. Now, Notification Services extends the core platform to include rich data-integration technology that begins to break down the walls between the database and the middleware technology that uses the database.

Microsoft licenses Notification Services, which is bundled as part of the core SQL Server 2000 data-management platform, the same way it licenses Analysis Services: Notification Services is free as long as the box you want to run it on already has a license for SQL Server. To deploy Notification Services on a new physical machine, you must buy a separate license of SQL Server for that machine. You can download Notification Services at http://www.microsoft.com/sql/ns/default.asp. This page includes links to a white paper, a guide to choosing the correct edition of Notification Services, and licensing FAQs.