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

On Mon, Apr 13, 2015 at 5:08 PM, Alvaro Herrera
<alvherre(at)2ndquadrant(dot)com> wrote:
> tgarnett(at)panjiva(dot)com wrote:
>
>> ERROR: could not access status of transaction 303450738
>> DETAIL: Could not open file "pg_multixact/members/7B49": No such file or
>> directory.
>
> Bruce and Kevin both pinged me about this issue recently. Turns out
> that I have an incomplete patch to close the problem. Just to clarify,
> this is a completely new problem, not related to #8673.
>
> The fix is to raise an ERROR when generating a new multixact, if we
> detect that doing so would get close to the oldest multixact that the
> system knows about.

I think we definitely need to do that ASAP. And possibly then force
an immediate minor release. Bugs that eat your data are bad, and we
have a customer hitting this completely independently of this report,
which makes this look like more than a theoretical problem.

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