Wow, is this fast! I'm impressed. The GROUP BY I left out for now, as I thought things would become to complicated, it could be the date though, column ab, for these are the same (in pairs). These two rows are a pair:
3830 | 2004-01-26 15:26:06 | 137 | 101 | 1169 | 137 | 101 | pin-mcr ok
3830 |...