Re: could not access status of transaction pg_multixact issue

jim_yates wrote:
> Alvaro Herrera-9 wrote
> >
> > There must have been some confusion somewhere; certainly you shouldn't
> > be subtracting anything. The subtraction was just suggested as a way to
> > determine the age. The value to update pg_database.datminmxid to is the
> > oldest one of all the relminmxid in pg_class; so if you have 8376 as the
> > minimum value there, that's what you set pg_database.datminmxid to. Not
> > the 21973 value.
> >
> > update pg_database set datminmxid='8376' where datname='production-copy';
>
> Ok, I'm still confused. Is the value to use the Max value of relminmxid
> from pg_class or the value of NextMultiXactId from pg_controldump? Or are
> these the same thing?

You need to *minimum* of all the values in relminmxid (excluding those
that are zero).

The pg_controldata value is a mechanism to determine which value is
minimum -- when there's been wraparound, the minimum might be "smaller
than zero", i.e. something like 4 thousand millions. I doubt this is
your case though.

--
Álvaro Herrera http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services