Hello, I will briefly recap the problem I have already reported a few weeks ago: I am using monetdb default branch (I did not compile the stable version because I need embedded python) and I have a large table (~80 GB). A simple query like SELECT * FROM large_table WHERE field=x, fails. mserver5 reports this error: mserver5: gdk_select.c:867: fullscan_int: Assertion `cnt < (bn)->S.capacity' failed. It seems that monet thinks it doesn’t have enough space to do a full scan of the table, maybe? (The machine has 800GB of free disk space and 30GB of RAM - Ubuntu 14.04). I was using a default branch of december 2015, I have tried to use the latest default branch (4/08/16), recompiled, installed but nothing, always the same error. So, as suggested, I have compiled the latest stable release (Jun2016-SP1). Now even a query which does not require monet to read the whole table (like SELECT * FROM large_table LIMIT 10 - This query worked fine in the default branch version) fails with ‘Program contains error’ message by client. Selecting a single column of the table works just fine. Moreover, with the stable release, the same issue arises with the second biggest table of the database (~35 GB). [Here you can find the configuration of MonetDB: http://pastie.org/private/r8gtssg944aqwnigrysa] All queries on all the other tables in the database (they are all much smaller than these two) work fine. I do not understand if the issue is in the size of table or somewhere else. How can I know what ‘error’ the message ‘program contains errors’ is referring to? NOTE: At the beginning, using the default compiled branch everything worked just fine! Every query on my large_table worked as expected. Then I had to recreate the database from scratch so I deleted the dbfarm and created a new one. That’s when this headache started… At this point I don’t know what to do, any help would be MUCH appreciated. Thanks, Stefano