what kind of differences will come up with using a standard SQLInstallation (MSSQLserver instead of EPOSERVER). Are there any behvings with which the neccessarity of using a named instance on a one Server platform (ePO+SQL) is explainable? Which side effects come up with this or are there any problems in a nonclustered envirnoment known?
Simpel question: Why use a named instance?
It is purely one of convenience of management. When using a dedicated SQL server there's no need to bother. When using a shared resource or a cluster it is highly advisable to seperate different sets of business functions into differing instances. This is largely an administrative concept but it does have some security involved since databases can theoretically access shared resources within the same instance.