Hi Andres,
> > > Looking for possible course of action. > > Probably simplest fix - drop and recreate these 6 affected users, but so > > far I willing spent some time research into this issue. > > Could you use pageinspect to get the infomasks for the affected tuples? > > Greetings, > > Andres Freund > For sample: postgres=# vacuum pg_catalog.pg_authid; ERROR: found xmin 2894889518 from before relfrozenxid 248712603 select ctid, xmin, xmax, cmin, cmax from pg_catalog.pg_authid where xmin::text::bigint=2894889518; ctid | xmin | xmax | cmin | cmax --------+------------+------+------+------ (1,26) | 2894889518 | 0 | 0 | 0 postgres=# SELECT * FROM heap_page_items(get_raw_page('pg_authid', 1)) where t_ctid::text='(1,26)'; -[ RECORD 1 ]----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- lp | 26 lp_off | 4656 lp_flags | 1 lp_len | 144 t_xmin | 2894889518 t_xmax | 0 t_field3 | 0 t_ctid | (1,26) t_infomask2 | 32779 t_infomask | 10507 t_hoff | 32 t_bits | 1111111111000000 t_oid | 189787727 Any new role created in DB instantly affected by this issue. In the same time: select relfrozenxid from pg_class where relname='pg_authid'; relfrozenxid -------------- 2863429136 So it's interesting where value of " from before relfrozenxid 248712603" come from. -- Maxim Boguk Senior Postgresql DBA http://dataegret.com/ <http://www.postgresql-consulting.com/> Phone RU: +7 985 433 0000 Phone UA: +380 99 143 0000 Phone AU: +61 45 218 5678 LinkedIn: http://www.linkedin.com/pub/maksym-boguk/80/b99/b1b Skype: maxim.boguk "Доктор, вы мне советовали так не делать, но почему мне по-прежнему больно когда я так делаю ещё раз?"