You can connect to any of the database servers that have been configured in the distributed server definition file (SDF). All QMF for WebSphere users use the same SDF. The SDF includes the technical information QMF for WebSphere needs to connect to the database servers and control resource usage. The SDF is created, maintained and distributed by the person who is responsible for configuring your QMF query environment.
The database servers that are available for you to use are listed in the All Servers branch of the Database Explorer tree when you open QMF for WebSphere.