Andres Freund writes:
> On 2020-04-01 19:57:32 -0400, Tom Lane wrote:
>> Agreed, but just knowing what the oldest xmin is doesn't help you
>> find *where* it is. Maybe what we need is a view showing all of
>> these potential sources of an old xmin.
> +1. This would be extermely useful. It's a v
Hi,
On 2020-04-01 19:57:32 -0400, Tom Lane wrote:
> Alvaro Herrera writes:
> > On 2020-Apr-01, Tom Lane wrote:
> >> The fact that I had to use max(age(...)) in that sample query
> >> hints at one reason: it's really hard to do arithmetic correctly
> >> on raw XIDs. Dealing with wraparound is a p
On Thu, Apr 2, 2020 at 12:13 AM Craig Ringer wrote:
>
>
>
>
> On Thu, 2 Apr 2020 at 07:57, Tom Lane wrote:
>>
>> Alvaro Herrera writes:
>> > On 2020-Apr-01, Tom Lane wrote:
>> >> The fact that I had to use max(age(...)) in that sample query
>> >> hints at one reason: it's really hard to do arith
On Thu, 2 Apr 2020 at 07:57, Tom Lane wrote:
> Alvaro Herrera writes:
> > On 2020-Apr-01, Tom Lane wrote:
> >> The fact that I had to use max(age(...)) in that sample query
> >> hints at one reason: it's really hard to do arithmetic correctly
> >> on raw XIDs. Dealing with wraparound is a probl
Alvaro Herrera writes:
> On 2020-Apr-01, Tom Lane wrote:
>> The fact that I had to use max(age(...)) in that sample query
>> hints at one reason: it's really hard to do arithmetic correctly
>> on raw XIDs. Dealing with wraparound is a problem, and knowing
>> what's past or future is even harder.
On Wed, Apr 1, 2020 at 5:58 PM Alvaro Herrera wrote:
>
> On 2020-Apr-01, Tom Lane wrote:
>
> > James Coleman writes:
> > > To my knowledge the current oldest xmin (GetOldestXmin() if I'm not
> > > mistaken) isn't exposed directly in any view or function by Postgres.
> >
> > You could do something
On 2020-Apr-01, Tom Lane wrote:
> James Coleman writes:
> > To my knowledge the current oldest xmin (GetOldestXmin() if I'm not
> > mistaken) isn't exposed directly in any view or function by Postgres.
>
> You could do something like
>
> select max(age(backend_xmin)) from pg_stat_activity;
>
>
James Coleman writes:
> To my knowledge the current oldest xmin (GetOldestXmin() if I'm not
> mistaken) isn't exposed directly in any view or function by Postgres.
You could do something like
select max(age(backend_xmin)) from pg_stat_activity;
though I'm not sure whether that accounts for abso
Currently there's no good way that I'm aware of for monitoring
software to check what the xmin horizon is being blocked at. You can
check pg_stat_replication and pg_replication_slots and
txid_snapshot_xmin(txid_current_snapshot()) and so on, but that list
can grow, and it means monitoring setups ne
