INF: SQL Small Business: Licensing, Connections, and Limitations (179856)

SUMMARY

This article describes the differences between the version of Microsoft SQL Server included with the Microsoft BackOffice Small Business Server and the retail version of SQL Server.

The version of SQL Server included with Small Business Server is very similar to Microsoft SQL Server 6.5, with Service Pack 3 applied. The main area of change is the manner in which licensing and user connections are managed (discussed below). Other changes include:

Setup

SQL Server Small Business Version setup uses an unattended installation script. There is no user interface and all default values are selected.

Total Disk Capacity

SQL Server Small Business Version will support up to 1 gigabyte (GB) of total database space. The total size of the user databases and log may not exceed 1 GB. This does not include the default space allocated for SQL Server Master, Model, MSDB, or Pubs databases. However, if these databases are expanded, the additional space will count against the 1 GB limit. Tempdb space is not counted against the limit no matter how large it is expanded to. Attempts to allocate space for a new or existing database such that the available 1 GB limit is exceeded, will fail with the following message:

SQL DMO
Error 1818 (SQL Server) CREATE/ALTER DATABASE failed
because resulting cumulative database size would exceed your
licensed limit of 1051 megabytes.

Books Online

There is a limited troubleshooting guide available for common problems, but SQL Server Books Online is not included.

Client Utilities Installation

SQL Server setup on the Small Business Server machine will automatically install the client utilities on the server. There is no setup program for installing the utilities on remote clients.

MORE INFORMATION

Microsoft BackOffice Small Business Server is available in 5- and 25-user license versions. Customers may purchase additional client add packs, but may not exceed 25 licensed users. SQL Server Small Business Version can accept as many users as are licensed for the Small Business Server suite. SQL Server Small Business Version can only be run on the version of Windows NT included with the Small Business Server. It will not install or run on any other version of Windows NT.

You can upgrade the individual components of the Small Business Server suite. You can also upgrade Small Business Server Windows NT to the full retail version of Windows NT, and the Small Business SQL Server will continue to work. Even if you upgrade, the SQL Server Small Business Version limitations outlined in this article still apply. Conversely, you may install full SQL Server on a Small Business version of Windows NT. In this situation, SQL Server has none of the Small Business version limitations, but Windows NT will be restricted to the Small Business Server number of licensed client connections (maximum of 25). You can not install SQL Server Small Business Version on full retail versions of Microsoft Windows NT Server.

For the Small Business Server, SQL Server capacity is limited using the Concurrent Work Limit (CWL). The capacity limit is set to allow good performance for the intended market of 5 to 25 users. As requests come to SQL Server, an active request count is maintained. When the CWL is reached, any further requests queue up and wait for an active request to complete. The CWL is set to 5 in the version of SQL Server that is included in Small Business Server version 4.0.

SQL Server will accept as many connections as are configured in the user connections parameter in sp_configure. (The default is 15, and may need to be increased.) With a 25-license Small Business Server, all 25 users will all be able to use SQL Server concurrently. All 25 will maintain their connections and work within the application. SQL Server is not limited to five users at a time by the CWL. However, SQL Server will only physically process five requests at a time. So if six users are trying to query SQL Server at the same time, the sixth one is blocked until one of the first five is completed. After this happens, and a request is available, the sixth user's query is processed. To the users, there is no noticeable effect. They are still active within the application, and are connected to SQL Server and working. In a worst case scenario, performance may be impacted.

However, for the Small Business Server market size (5 to 25 users), performance should not be an issue. SQL Server queries should be short and concise. In a real-world application, the likelihood that more than five of 25 users (20 percent) will concurrently run resource intensive queries for long periods of time is negligible, if the application is well-designed. Performance degradation should be minimal even when the maximum number of users are connected.

One implication of the CWL is that new connections to SQL Server may appear to hang, or possibly timeout, during periods of heavy activity. The sp_server_info stored procedure is executed for any new connection made to SQL Server, before the connection is available for client use. If the number of active requests has already reached the CWL at the time of the connection (that is, five SQL Server requests are currently being processed), these queries must wait for the next available request before they are executed. At this point, the connection will appear to hang. If a login timeout has been specified for the application, and the connection is still waiting when this timeout value is reached, the connection will fail. Setting the login timeout to 0 (zero) will allow the connection to wait until it can be processed. This situation should be very rare for applications in the 5- to 25-user range.