If you look at the queue_log table, it should be trivial seeing which fireld is which. On the other side, I personally do not recommend having Asterisk log directly to MySQl, because:
1. It's more likely for a networked MySQL to be down than not to be able to write lto a local file. In a sense the local file acts as a "local buffer" and "natural backup".
2. qloaderd syncs with usually one second or less of delay, so ut should not change much.
Feel free to share your experience, whether you succeed or not