SQL-NS is available in four editions of SQL Server 2005: Developer Edition, Evaluation Edition, Standard Edition, and Enterprise Edition. The functionality of Developer Edition and Evaluation Edition is the same as Enterprise Edition; the difference is that Developer Edition is licensed only for development use and Evaluation Edition is licensed only for evaluation purposesneither can be put into production. Therefore, when comparing the editions, we usually distinguish only the Standard and Enterprise Editions in terms of SQL-NS features. Developer and Evaluation Editions can be substituted for Enterprise Edition in development and evaluation environments. Caution SQL-NS is not supported on the Express or Workgroup editions of SQL Server 2005. Although the core SQL-NS functionality in the two editions is similar, the Enterprise Edition supports several features that make it more scalable and therefore capable of supporting the largest applications. Specifically, Enterprise Edition supports the following features, which Standard Edition does not:
It should be noted that even in the Standard Edition, SQL-NS does support very large applications because of the inherent scalability of the application model and execution engine. The Enterprise Edition features take scalability even further. Because the SQL-NS components may be installed independently of the SQL Server used to host SQL-NS applications (especially in remote SQL Server configurations), it's possible for their respective editions to differ. For example, the SQL-NS tools and engine may be Enterprise Edition (because they were installed from a SQL Server 2005 Enterprise Edition CD), but the SQL Server itself may be Standard Edition. The following are the licensing restrictions on edition mismatches:
The edition of the SQL-NS tools used to create an application determine the functionality that may be used in that application. For example, an application that uses multicast delivery, an Enterprise Edition feature, can only be built using the Enterprise Edition SQL-NS tools. Only an Enterprise Edition SQL-NS engine may run such an application. You can use the SQL-NS tools and engine from either edition to work through the samples in this book. Subsequent chapters cover features that are available only in the Enterprise Edition (they are all marked as such), but those features are not used in the samples. |