On 2018-05-24 16:49:40 -0400, Alvaro Herrera wrote: > BTW is it just a coincidence or are all the affected tables pg_authid? > Maybe the problem is shared relations ..? Maybe the fact that they have > separate relfrozenxid (!?) in different databases? Yes, that appears to be part of the problem. I've looked at a number of shared relation related codepaths, but so far my theory is that the relcache is wrong. Note that one of the reports in this thread clearly had a different relcache relfrozenxid than in the catalog. Then there's also: http://archives.postgresql.org/message-id/1527193504642.36340%40amazon.com Greetings, Andres Freund