Hello Scott, Thank you for your help and pointing me into some directions and also for making me aware that some things are more important! :-)
I did read most of the wiki and many blogs and websites about Cassandra before deciding to go with it, even did several test installations and small load tests to compare Cassandra with other similar systems. It is hard to learn everything you really need to know before you really use it and run into the first trouble :-) So I followed your advise and read some of the mentioned pages again and understood some more things that I wasn't paying so much attention to before. There also seem to be some changes since the 0.4 version I based my decision on in the beginning. To make it short: My questions are now answered :-) Thanks again, Mario