Hi,
I have written a similar program in C. It imports over 2 Mill. connection log lines in just about 20 minutes. Other scripted methods, such as via Perl, appear to take a bit more time, CPU and RAM, which is why I chose C.
It parses logs (conn.log only right now) from Bro and puts the contents into MySQL.
The code is autoconf’ed, so you might want to give it a try. I also include the SQL Table layout I used.
I have the code up here: https://sourceforge.net/projects/bro-tools/
HTH
Cheers!
–Christopher