Re: Long running query causing XID limit breach

On Thu, May 23, 2024 at 9:00 AM Muhammad Salahuddin Manzoor <
salahuddin(dot)m(at)bitnine(dot)net> wrote:

> Greetings,
>
> In high-transaction environments like yours, it may be necessary to
> supplement this with manual vacuuming.
>
> Few Recommendations
>
> Monitor Long-Running Queries try to optimize.
> Optimize Autovacuum.
> Partitioning.
> Adopt Vacuum Strategy after peak hours.
>
> We have these big tables already partitioned. So does "vacuum table_name"
will endup scanning whole table or just the latest/live partition which is
getting loaded currently? and do you mean to say running command "vacuum
table_name;" frequently on selective tables that are experiencing heavy DML
? Hope this won't lock the table anyway because the data will be
written/read from these tables 24/7.

When you say, "optimize autovacuum" does it mean to set a higher value
of "autovacuum_max_workers"
and "autovacuum_freeze_max_age"?

Considering we have ~4 billion rows inserted daily into the table and there
is limit of ~2billion to the "Maximumusedtxnids", what threshold should we
set for the alerting and to have enough time at hand to fix this issue?