Rabauke wrote a very good blog post about debugging Nepomuk and Virtuoso query performance on OpenSuse.
Also David Faure posted a Virtuoso patch on the Nepomuk mailing list which makes the Virtuoso status() command output the full queries instead of the truncated ones. I will try to get the latter into Virtuoso upstream, maybe with an additional parameter to the function.
If I learned anything at the Nepomuk workshop it is that too much information is just in my head and nowhere else. I tried to share it by writing API documentation and tutorials and blogs. But it never is enough. So today comes another dump from my brain: Nepomuk tips and tricks, a new chapter in the Nepomuk tutorial series. I hope it helps you to make more of the technologies Nepomuk provides.
Trueg's Blog 