Hi, We had such a weird issue here, we are using Feb2009-SuperBall package, we managed get our data into monetdb, but some how when we try to delete data, it reappears under single user or readonly mode. Here is what we did, we put database in normal mode without gdk_single_user and gdk_readonly in monetdb5.conf. Issue a delete sql statement in mclient, now we query the data, seem the data is gone, and then we stop the database server, and start it in readonly mode. Then query the data again, the data come back!!! Seems to us the monetdb did not sync the memory with disk. Any ideas? Allen