In the following join: select * from computer,ethernet where computer.ethernet=ethernet.id; One of the instances of computer has no ethernet value. I thought computer.ethernet=ethernet.id would just evaluate to false for this instance, yet pqReadData() -- backend closed the channel unexpectedly. This probably means the backend terminated abnormally before or while processing the request. We have lost the connection to the backend, so further processing is impossible. Terminating. happened instead. Is this right? Cheers, Patrick (source supped Sep 9)