Support for simultaneous queries / read locking

We are looking to use MonetDb as the backend of a multi-user BI system. Before we get too far down the road with development, I'm wondering how MonetDb will perform with 10, 50, 100, 1000 simultaneous users? We are not concerned about writes - just reads, as we plan to do updates as a nightly batch process when we can tolerate a small window of performance downgrades on the queries. Is there any read-locking that limits concurrent queries from accessing the same data? If so, is it at the column level, or finer grained? Does anyone have experience using MonetDb for handling lots of concurrent queries? Thanks in advance for any info. -- Mark