Me again.
I'm testing an upgrade of a database from 9.2.10 to 9.2.22. The upgrade seemingly had no problems and I started the DB. However when I went to look at some vacuum-related status, every table had n_dead_tup and n_live_tup = 0.
For what it's worth, this DB was a clone of a prod standby. I didn't think to check the stats after opening the new clone (renamed the recovery.conf), so I can't say for sure what it looked like prior to upgrade. I've kicked off a DB-wide analyze but obviously that takes a long time and more or less would mean prod app downtime as the optimizer would make all sorts of goofy decisions until the stats are in place.
I just wanted to ask here if anything like this is known. I know 10->22 is a bit of a leap but it's still the same major branch so I didn't expect any trouble. My other tests in small sandboxes were from 9.2.18 or .21 to 9.2.22 and had no problems like this.