Re: ERROR: MultiXactId 3268957 has not been created yet -- apparent wraparound after missused pg_resetxlogs

On Mon, Oct 16, 2017 at 5:41 PM, alain radix <alain(dot)radix(at)gmail(dot)com> wrote:
> I’m facing a problem with a PostgreSQL 9.6.2 reporting this error when
> selecting a table
>
> ERROR: MultiXactId 3268957 has not been created yet -- apparent wraparound
>
> The root cause is not a Postgres bug but a buggy person that used
> pg_resetxlogs obviously without reading or understanding the documentation.

Hmm, I hope you patched that person...

> I’m trying to extract data from the db to create a new one ;-)
>
> But pg_dump logically end with the same error.
>
> I’ve seen the row with t_max = 3268957 page_inspect, I might use it to
> extract row from the page, but this will not be quite easy.

Not sure if this would work, but maybe try BEGIN ... UPDATE the row,
perhaps via TID qual ... ROLLBACK?

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company