Re: Error on vacuum: xmin before relfrozenxid

Hi!

> 24 мая 2018 г., в 0:55, Paolo Crosato <paolo.crosato@gmail.com> написал(а):
>
> 1) VACUUM FULL was issued after the first time the error occurred, and a couple of times later. CLUSTER was never
run.
> 2) Several failovers tests were perfomed before the cluster was moved to production. However, before the move, the
wholecluster was wiped, including all the application and monitoring users. After the db was moved to production, a
coupleof users were added without any problem. 
> 3) No, even if the replication level is set to logical in postgresql.conf, we only use streaming replication.

I've encountered seemingly similar ERROR:
[ 2018-05-22 15:04:03.270 MSK ,,,281756,XX001 ]:ERROR:  found xmin 747375134 from before relfrozenxid 2467346321
[ 2018-05-22 15:04:03.270 MSK ,,,281756,XX001 ]:CONTEXT:  automatic vacuum of table "postgres.pg_catalog.pg_database"

Table pg_database, probably, was not changed anyhow for a long period of database exploitation.
Unfortunately, I've found out this only there were million of xids left and had to vacuum freeze db in single user mode
asap.But, probably, I will be able to restore database from backups and inspect it, if necessary. Though first
occurrenceof this error was beyond recovery window. 

Best regards, Andrey Borodin.