I consider BaseX in the context of BigData and try to compare it with other noSQL databases. Yet, there is no replication or partition mechanism implemented and BaseX is a database with a single point of failure. Am I right?

Yes, you are right. For some more information on what has been done so far, feel free to check out some of our publications (e.g. [1,2]).

Thus, my question is, how can I classify the System BaseX regarding the CAP-Theorem?

Well, what classification do you currently think it is? What do you think is exactly the challenge in answering this question? ;) Cheers, Christian [1] http://files.basex.org/publications/Kirsten%20[2014],%20Efficient%20and%20failure-aware%20replication%20of%20an%20XML%20database.pdf [2] http://files.basex.org/publications/Lewandowski%20[2012],%20Using%20Map%20and%20Reduce%20for%20Querying%20Distributed%20XML%20Data.pdf