[basex-talk] xquery update impact on server?

All: I'm running an long "xquery delete node" on one of my database and this pretty much seem to make my server unavailable for other operations. I expect this query to run for a few hours (affecting a few million nodes, database is around 800Mb). I'm running this on a Amazon EC2 small instance (1 CPU, 1.7Gb RAM) and the CPU has been stuck at 100%. If I attempt to query any database on the server (not only the one being updated), I basically don't get anything back. So do heavy xquery update requests basically lock down the server? Anyone else having similar experience? Feedback/suggestions? best *P