Thanks for you ip. I'm not sure I can pre load the counters with zero as I don't know what the keys will be until I read the tcpdump input. The table format is currently:
ip|count_in|count_out|count_cross
But this is starting to get off topic and I should read up more on Mysql. (I had hoped, that there was a guide out there that talked about how to drive BerkeleyDB in full {lets do manual locking in perl}) mode and that my search fu was lacking.