> Yes. Our implementation restrictions preclude access to the contents > of another session's temp tables, but it is not forbidden to do DDL > on them so long as no content access is required. (Without this, > it'd be problematic for example to clean out a crashed session's temp > tables. See the "orphan temporary tables" logic in autovacuum.c.)
Indeed, a potentially dangerous situation may arise when both the autovacuum and client process attempt to delete the contents of a temporary namespace. But there is a patch (6faca9ae2878c8f642a2e5748d2dbb2b91341bec)thatprotectsusfrom race condition in this case. -- Best regards,