Wow ! You pretty much answered ALL my questions, expressed or otherwise ! I'll have to re-read your answer a few times for everything to sink in. Initially I thought the query optimizer would be smart enough to find the best way to execute the query, but it seems it is not the case. Can't blame it, of course. I will need to create the indexes on Traffic (checkDate, name, flow) and on People (name, nick). Also thanks for the side advice, it is much appreciated.