Tobias Lott <tobias.lott@xxxxxxxxxxxx> writes: > Yes that's strange. A lot of pg_XX tables are skipped, but some of these > pg_temp schemas cause errors. > Could it be connected to a migration of the database (from an instance > running PostgreSQL 9.6 to an instance running PostgreSQL 12) done a few > weeks ago? I wouldn't have expected a migration to bring any temp tables forward. Have you had any crashes on this instance (post-migration)? A possible theory is that crashed backend(s) left behind some temp tables, and then if vacuumdb's backend process re-uses the backend ID (which determines the NN in pg_temp_NN) of one of those sessions, it would think those temp tables are its own and try to vacuum them. Or at least I think it might. That still fails to explain the permissions errors in any detail, but at least it offers a reason why vacuumdb would even be going anywhere near a temp table. regards, tom lane
