Here I am, 9:35 PM, 2 hours past my regular bedtime.  582,000 records processed so far. it's been 3 hours, probably more.  And here I sit, watching yellow boxes, and waiting for an SSIS package to finish running.
I'm testing some updates done by myself and some team members, and need to verify that the package can successfully complete. When it's done, I need to test the next batch. And I need to have them all done tonight, because I'm taking off tomorrow.
But I don't know how many rows are coming out of the data source!
And therein lies the problem. I forgot to check before I ran the package to see how many rows the source query will return with the new set of test data. It might be just a few more rows. It might be a few million.
So here is a tip from me to you: always test your source query before running your packages.
Because watching yellow boxes sucks.Here I am, 9:50 PM. 621,000 records processed so far...
 Or last.
 I have small kids, what can I say?
 I'm pulling the data from a remote Oracle database on the other side of a VPN - LAN-local performance had better be a lot better than this, eh?