Re: Unexpected behavior when setting "idle_replication_slot_timeout"

"David G. Johnston" <david(dot)g(dot)johnston(at)gmail(dot)com> writes:
> On Saturday, July 5, 2025, Fujii Masao <masao(dot)fujii(at)oss(dot)nttdata(dot)com> wrote:
>> Do you see any serious downside to switching the unit to seconds? I don't
>> think it introduces any serious issues. On the contrary, it gives users
>> finer
>> control over the timeout, and additionally works around the issue
>> that we're discussing here.

> I do not, and would rather we make the change. Minutes are an
> unconventional base unit for time in our world and should be avoided.

By my count, there are ten GUCs declared with GUC_UNIT_S and three
with GUC_UNIT_MIN. I'd say that there may be some lean towards
seconds but David's argument seems like pure hyperbole.

I'm kind of down on changing the unit, because it will *silently*
break configuration files where the value was set without a unit.

May I suggest an alternative? We could change the variable from int
to float type and continue to specify it in minutes. That will have
exactly zero compatibility impact, it allows sub-minute values to
be selected at need, and it removes the need for hair-splitting
documentation about what the rounding rules are.

We previously did the same with vacuum_cost_delay to avoid worries
about how to specify sub-millisecond precision for that. So the
infrastructure is already in place, I think. The patch will be
different from what is proposed but should need to touch pretty
much the same places.

regards, tom lane