Apologizes for not noticing this earlier, but as part of TRUNK-3915, we are added a not-null constraint to the uuid column of the obs table.
Previously, we’ve noticed high performance impacts when trying to make schema changes to a very large table such as the obs table. I’m currently testing out the 1.10.4 platform release again a copy of our production database at UHM, (which has over 11 million obs) and the update did appear to work successfully, but not without hanging my development IntelliJ/Jetty instance in the process. I will add a warning about this to the 1.10.4 release notes.