Re: BUG #12990: Missing pg_multixact/members files (appears to have wrapped, then truncated)

On Mon, 27 Apr 2015 11:59:10 -0300
Alvaro Herrera <alvherre@2ndquadrant.com> wrote:

> I think we can easily determine the rate of multixact member space
> consumption and compare to the rate of multixact ID consumption;
> considering the historical multixact size (number of members per
> multixact) it would be possible to change the freeze ages by the same
> fraction, so that autovac effectively behaves as if the members
> consumption rate is what is driving the freezing instead of ID
> consumption rate.  That way, we don't have to jump suddenly from
> "normal" to "emergency" behavior as some fixed threshold.

I would like to add a data point: one of my clients has a plpgsql function
that manages to use ten to 30 thousand multixact ids per invocation. It
interacts with a remote resource and sets an exception handler on a per
item basis to catch errors on the remote call.

-dg


--
David Gould              510 282 0869         daveg@sonic.net
If simplicity worked, the world would be overrun with insects.