1.1. SQL Server 2008: evolution or revolution?

When Microsoft released SQL Server 2005, the general consensus was that SQL Server had finally arrived as an enterprise class database management system. With a host of new features, including Common Language Runtime (CLR) integration, dynamic management views/functions, and online index rebuilds, it was correctly considered a revolutionary release of the product, coming some 12 years after the first Microsoft release of SQL Server, as shown in figure 1.1.

Figure 1.1. From there to here: a brief history of SQL Server from 1993 to today
 

While SQL Server 2008 improves many of the features first introduced in 2005, it too has an impressive collection of new features, many of which we'll cover throughout this book. From a DBA perspective, the standout new features include the following:

• Policy-based management—Arguably the most significant new SQL Server 2008 feature for the DBA, policy-based management dramatically simplifies the process of managing a large number of SQL Server instances through the ability to define and apply configuration policies. As you'll see in chapter 8, changes that violate policy can either be prevented or generate alerts, with groups of servers and instances remotely reconfigurable at the click of a button.

• Resource Governor—While SQL Server 2005 included coarse-grained control of server resource usage via instance memory caps, CPU affinity, and Query Governor Cost Limit, SQL Server 2008 permits the definition of resource pools into which incoming connections are classified via group membership. As you'll see in chapter 16, each pool's memory and CPU usage can be constrained, therefore enabling more predictable performance, particularly for mixed-purpose SQL Server instances—for example, a data entry environment that's also used for reporting purposes.

• Data Collector—Covered in chapter 15, the new Data Collector feature enables the collection of performance and management-related information such as performance monitor counters, dynamic management view data, and query statistics. In addition to the automated collection, upload, and archival of such information, numerous reports are provided to enable the analysis of the collected data over time, making it a powerful and low-maintenance tool for baseline analysis and various other tasks.

• Backup and data compression—In SQL Server 2005 and earlier, third-party utilities were used to compress backups. SQL Server 2008 includes not only backup compression, but also the ability to compress data within the database, enabling significant disk space and cost savings, and in some cases, a significant performance boost. We'll cover data and backup compression in chapters 9 and 10.

• Transparent Data Encryption—SQL Server 2005 included the ability to encrypt individual columns within a table, but no way of encrypting the entire database and associated backup files. As such, anyone with access to the physical data files or backup files could potentially take the database offsite and have full access. SQL Server 2008 introduces the Transparent Data Encryption (TDE) feature for exactly this purpose; see chapter 6 for more.

In addition to these major new features are a whole range of others, including T-SQL enhancements, fine-grained auditing, support for geospatial data, NTFS-based FileStream binary large objects (BLOBs), and IntelliSense support. I believe that the release of SQL Server 2008 is as significant as the release of 2005.

A number of the new features introduced in SQL Server 2008 are only available in the Enterprise edition of the product. As we move through the book, I'll point out such features wherever possible, but now is a good time for a broad overview of the various SQL Server 2008 editions and their features.