Been looking at pt-upgrade recently, running it against a couple of test systems.
It’s reported “Row diffs: 3” on a couple of runs.
Does ‘pt-upgrade’ sort data it gets back before comparing rows? - I’m just wondering as the original query has no ORDER BY and looks like it might be returning the same rows, in different orders on both servers (the client doesn’t care about this as it’s just iterating the whole lot).
But just wondered if lack of ORDER BY if it results in a difference in row orders is going to upset pt-upgrade, or whether it orders the rows effectively before it ‘diffs’ them?