Because Microsoft® SQL Server™ 2000 can be set up to include one or more named instances, with or instead of a default instance, new naming conventions are used to distinguish between instances.
In earlier versions, a SQL Server installation is identified by computer name. In SQL Server 2000, only the default instance is identified solely by computer name. A named instance is identified by a combination of computer name and instance name. This instance name is also reflected in the names of the associated SQL Server services.
Note There can be only one default instance of SQL Server for each computer. It can be an intact SQL Server version 6.5 or SQL Server version 7.0 installation, or it can be an installation of SQL Server 2000 set up as the default instance. In either case, the default instance uses the same service names, registry structure, network listening points, and other defaults used in SQL Server 7.0.
Service Names for Default and Named Instances
When you install a default instance of SQL Server, the service names remain MSSQLServer and SQLServerAgent (the same as in SQL Server 7.0).
When you install a named instance of SQL Server, the service names are changed to:
- MSSQL$InstanceName for the MSSQLServer service.
- SQLAgent$InstanceName for the SQLServerAgent service.
The Microsoft Distributed Transaction Coordinator and Microsoft Search services are installed only once, and can be used simultaneously by every installed instance of SQL Server.