I am using MonetDB-11.27.9 on ubuntu 17.04. The client was compiled from the source code. I am trying to run the following query on your database select distinct T.src as author, T1.src as coauthor, json.tojsonarray(T1.dst) as papers from edges1000 as T, edges1000 as T1 where T.dst = T1.dst AND T.src <> T1.src group by T.src, T1.src ; When I run this query over a table with at most 10^4 entries, the mclient client quits. If I try to execute the same qury via JDBC, I receive an error that tells me "maybe mserver closed unexpectedly". On the other hand, the server is still alive and responsive if I afterwards run the query either oover mclient or JDBC over a table having less data (edges10). Is that a problem of memory allocation ? Is there a way to solve this issue? I'm using the default configuration, and compiled the source code using "autoreconf -if" first. Thanks in advance for your support, Bergami G