I'm running the built in backup routine right now in preparation for going from 7.2.2 to 7.3. It's on row 183,500 and counting. By its name, I'm worrying that it's spending all this time backing up data that was temporary for some past import.
Is this a table that's actually used for content? Maybe I'm just thrown off by the name.
Looking forward in my SQL administration tool, I see the posts table has 405,870 rows and the referer_log table has 1,073,712 rows. So it is going to take hours to back those up. I understand the posts table is necessary

However, what is the referer_log table? Do I need all 1 million + rows?