Microsoft recognizes that there is a plethora of database users with disparate needs. They therefore have released the following six versions of SQL Server 2005:

• SQL Server 2005 Express Edition

• SQL Server 2005 Workgroup Edition

• SQL Server 2005 Developer Edition

• SQL Server 2005 Standard Edition

• SQL Server 2005 Enterprise Edition

• SQL Server 2005 Mobile Edition

SQL Server 2005 Express Edition

SQL Server 2005 Express provides a great means of getting started with SQL Server. It offers a robust, reliable, stable environment that is free and easy to use. It provides the same protection and information management provided by the more sophisticated versions of SQL Server. Other advantages of SQL Server Express include

• Easy installation

• Lightweight management and query editing tool

• Support for Windows authentication

• "Secure by Default" settings

• Royalty-free distribution

• Rich database functionality, including triggers, stored procedures, functions, extended indexes, and Transact-SQL support

• XML Support

• Deep integration with Visual Studio 2005

SQL Server 2005 Express has a few disadvantages that make it unusable in many situations. These include

• Support for only one gigabyte of RAM

• Support for a four-gigabyte maximum database size

• Support for only one CPU

• Absence of the SQL Agent Job Scheduling Service

• Absence of the Database Tuning Advisor

SQL Server 2005 Workgroup Edition

SQL Server Workgroup Edition provides a great solution for small organizations or workgroups within larger entities. It includes a rich feature set, but is affordable and simple to work with. Other valuable features include the fact that there is no limit on database size and that it supports the SQL Agent Job Scheduling Service. The disadvantages of SQL Server 2005 Workgroup Edition include

• Support for only three gigabytes of RAM

• Support for only two CPUs

• Absence of the Database Tuning Advisor

SQL Server 2005 Developer Edition

SQL Server 2005 Developer Edition is designed specifically for developers who are building SQL Server 2005 applications. It includes all functionality of SQL Server 2005 Enterprise Edition, but with a special license that limits its use to development and testing. Its license specifies that you cannot use it for production development. For more details about the features of SQL Server 2005 Developer Edition, see the section "SQL Server 2005 Enterprise Edition" later in this section.

SQL Server 2005 Standard Edition

SQL Server Standard Edition provides an affordable option for small- and medium-sized businesses. It includes all functionality required for non-critical e-commerce, data warehousing, and line-of-business solutions. The advantages of SQL Server 2005 Standard Edition include

• RAM limited solely by operating system RAM

• No limit for database size

• Full 64-bit support

• Database mirroring

• Failover clustering

• Inclusion of the Database Tuning Advisor

• Inclusion of the full-featured Management Studio

• Inclusion of the Profiler

• Inclusion of the SQL Agent Job Scheduling Service

The disadvantages of SQL Server 2005 Standard Edition include

• Support for only four CPUs

• No support for online indexing

• No support online restore

• No support for fast recovery

SQL Server 2005 Enterprise Edition

SQL Server 2005 Enterprise Edition includes all the tools that you need to manage an enterprise database management system. It offers a complete set of enterprise management and business intelligence features, and provides the highest levels of scalability and availability of all the SQL Server 2005 editions. It supports an unlimited number of CPUs and provides all the features unavailable in the other versions of SQL Server 2005.

SQL Server 2005 Mobile Edition

SQL Server 2005 Mobile Edition enables you to easily port corporate applications over to mobile devices. SQL Server 2005 Mobile Edition offers many advantages. They include

• Inclusion of SQL Workbench (a tool that replaces SQL Server 2005 Management Studio)

• Full integration with SQL Server 2005

• Inclusion of synchronization functionality

• Excellent reliability and performance due to a revamped storage engine and an improved query processor

• Multi-user support via multi-user synchronization and row-level locking

• Full integration with Visual Studio 2005

• Increased device support