Re: pg_attribute, pg_class, pg_depend grow huge in count and size with multiple tenants.

Hi,

On Fri, May 8, 2020 at 3:53 AM Laurenz Albe <laurenz(dot)albe(at)cybertec(dot)at>
wrote:

> On Fri, 2020-05-08 at 03:47 -0300, Avinash Kumar wrote:
> > > Just set "autovacuum_max_workers" higher.
> >
> > No, that wouldn't help. If you just increase autovacuum_max_workers, the
> total cost limit of
> > autovacuum_vacuum_cost_limit (or vacuum_cost_limit) is shared by so many
> workers and it
> > further delays autovacuum per each worker. Instead you need to increase
> autovacuum_vacuum_cost_limit
> > as well when you increase the number of workers.
>
> True, I should have mentioned that.
>
> > But, if you do that and also increase workers, well, you would easily
> reach the limitations
> > of the disk. I am not sure it is anywhere advised to have 20
> autovacuum_max_workers unless
> > i have a disk with lots of IOPS and with very tiny tables across all the
> databases.
>
> Sure, if you have a high database load, you will at some point exceed the
> limits of
> the machine, which is not surprising. What I am trying to say is that you
> have to ramp
> up the resources for autovacuum together with increasing the overall
> workload.
> You should consider autovacuum as part of that workload.
>
> If your machine cannot cope with the workload any more, you have to scale,
> which
> is easily done by adding more machines if you have many databases.
>
Agreed. Getting back to the original question asked by Sammy, i think it is
still bad to create 2000 databases for storing 2000 clients/(schemas) for a
multi-tenant setup.

>
> Yours,
> Laurenz Albe
> --
> Cybertec | https://www.cybertec-postgresql.com
>
>

--
Regards,
Avinash Vallarapu