At TechEd Europe last week, Microsoft announced the release of SQL Server 2005 Express--the next generation of Microsoft SQL Server Desktop Engine (MSDE). SQL Server Express is built on SQL Server 2005 core technology and fixes many of MSDE's usage problems. The release also adds a host of new features, such as an advanced query optimizer that automatically optimizes queries, automated tuning, wizards for common tasks, a computer manager for starting and stopping services, automated servicing and patching, and a new XCopy feature that I'll tell you about in a minute. Because of these enhancements, SQL Server Express should be a big hit with customers who have worked with MSDE in the past. In addition, SQL Server 2005 Express will now make it possible for customers with simple database needs to get a powerful relational database engine for free. Yes, free. For a full list of SQL Server Express features, see http://www.microsoft.com/sql/express.

How does SQL Server Express compare to MSDE and the full version of SQL Server 2005? A rose by any other name is still a rose, and so it is with MSDE. But some customers haven't figured out that MSDE is simply a slimmed-down version of SQL Server. MSDE is free; however, the many different ways that you can acquire MSDE all have particular licensing and redistribution rules. MSDE doesn't include any GUI administration tools. So even though it's free, how good a value is MSDE if you can't easily administer it? MSDE also includes a performance governor that limits MSDE's usefulness in various situations because it's difficult to predict how and when the governor will restrict MSDE performance.

The price of SQL Server Express is also right. In comparison with MSDE, SQL Server Express is completely free and provides royalty-free distribution. SQL Server Express will include a GUI tool called SQL Server Express Manager. Although this tool isn't available yet, my colleagues at Microsoft assure me that the tool will be useful for basic administration and query-building tasks. SQL Server Express's governor, in contrast to MSDE's, is simple to understand: SQL Express uses a single processor--that's the only governor. SQL Server Express supports only one CPU, but you can install it on a machine with more than one processor. Microsoft has also chosen a simplified product name, clearly communicating that SQL Server Express is based on SQL Server core technology.

SQL Server Express is significantly more usable than MSDE, but MSDE does have a few features not included in SQL Server Express. For example, SQL Server Express lacks a Data Transformation Services (DTS) runtime, support to act as a replication publisher, and SQL Agent. SQL Server Express is a powerful relational engine without the additional features that are included in a full version of SQL Server. Would it be nice to have some of those additional features? Sure, but I suspect that Microsoft wants us to pay for them. SQL Server Express is a useful product to consider for a production database if you simply need a relational engine. Like MSDE, it's also a nice addition to a larger SQL Server implementation if you need a local database.

Now, let's look at how SQL Server Express compares to the upcoming release of SQL Server, SQL Server 2005. Not surprisingly, SQL Server Express lacks a number of important enterprise database features. The product doesn't include high availability features such as data mirroring and clustering, full-text search, SQL Agent, DTS, Reporting Services, Analysis Services, Notification Services, or SQL Server 2005's full management-tools suite called SQL Management Studio (which replaces Enterprise Manager). But SQL Server Express can deploy databases through the new XCopy feature, which makes moving SQL Server databases around your network as easy as moving a Microsoft Access MDB file. XCopy will make it easier for Independent Software Vendors (ISVs) and OEMs to integrate SQL Server technology into their products. SQL Server Express also offers a tremendous return on investment (ROI). Few customers today can successfully use MSDE as a production database. However, I expect that many customers will able to successfully deploy SQL Server Express as a production database for numerous low-end database needs. The lack of a GUI for MSDE made this difficult. The addition of a GUI administration tool along with an easier-to-understand performance governor will make SQL Server Express practical for many low-end production needs. ROI numbers are always great when you get true production capabilities for free.

According to Microsoft, SQL Server Express is free "because we believe that helping developers build great applications drives long-term customer adoption." I'm sure thoughts of the free, open-source MySQL database didn't enter into the decision-making process at all. But consider all the functionality that SQL Server Express offers, and you'll realize that the database provides a lot of database-processing power absolutely free--no strings attached. Customers will be able to deploy full SQL Server-based applications on a free version of SQL Server that shares the same core engine as SQL Server 2005. So if you've been chomping at the bit for SQL Server 2005, you can play with SQL Server Express today. Download the documents and dig in!