You KNOW (from years of experience) that it is difficult, if not impossible, to assume that the stream is going to give you data that you can simply capture and dump into a database, for further analysis and reporting.
The fact is that 99.99% of the time I can assume exactly that, because I have coordinated with the users and other admins and we have all agreed to a process. It only goes bad when someone goes rogue. Or when it's a very legitimate mistake that doesn't happen again. Without this, there would be no business. You can't run 60m records through each day without a lot of assumptions (aka trust, confidence, understanding, respect, courtesy, etc.).