Hello Ian I just tried to repeat what you found and I got the expected value for weight (weight=4) in my output. However I think it quite probable there is a bug that manifests under the right conditions, so I need you to provide some configuration information: * your system (32-bit, 64-bit, number of CPU cores, which operating system distribution, and kernel version) * either your compiler version, or did you install from a binary package, if so which version, where from? * contents of /etc/my.cnf or any other mysql config files TBH I am not sure what else to ask for, perhaps the output from SHOW GLOBAL VARIABLES so I can compare it to my own build, but that is quite a large volume of information, so feel free to pastebin it or something or create a bug against https://bugs.launchpad.net/oqgraph and attach it there thanks, Andrew