We also ran into this issue a few months ago. Our problem is our data model for the table in question is a mess, with literally hundreds of foreign keys pointin

We also ran into this issue a few months ago. Our problem is our data model for the table in question is a mess, with literally hundreds of foreign keys pointing at that ID column (so all of those tables would need to be altered as well). Migrating all of those would have resulted in an unacceptably long downtime (i.e. multiple days). We started down that path, but quickly realized it wasn't a viable option. So, plan B... It's a signed integer... The auto increment started at 1 and counted up from there... We literally had 50% of the ID space still available to us. So now we've started at -1 and are counting our way down from there. Obviously we're adding rows a lot faster now than we were at the beginning of time, but it has bought us more than enough time to fix the issue properly. It took a bit of cleverness to get those negative IDs (MySQL won't let you set the auto increment start point to a value less than the current max ID), but the end result is that we got back up and running in a couple hours, as opposed to the multiple days we initially thought we were looking at.