Re: Table-level log_autovacuum_min_duration

On Thu, Feb 12, 2015 at 5:44 PM, Naoya Anzai <anzai-naoya(at)mxu(dot)nes(dot)nec(dot)co(dot)jp>
wrote:

> Hi, Michael-san
>
> > An updated patch is attached,
>
> I'm sorry for confusing you.
>
> I think you don't have to implement this code to disable this
> feature with using value "-2".Because this use case is a rare case,
> and there is a practical workaround using huge value like "2e9".
> (You suggested "2e9" to me, didn't you? :) ) So, please remove this code.
>

I will clean up the code.

> > Well, I see your point but this is not completely true: we could as
> > well rely entirely on this parameter instead of VACOPT_VERBOSE to
> > determine if autovacuum, a vacuum or an analyze are in verbose mode,
> > and remove VACOPT_VERBOSE, but I can imagine people complaining if
> > VACOPT_VERBOSE is removed. So let's set it up unconditionally to -1 in
> > gram.y for now. However if people think that it is fine to remove
> > VACOPT_VERBOSE, we could use exclusively this parameter in VacuumStmt.
> > Or even add sanity checks at the top of vacuum() to ensure that
> > VACOPT_VERBOSE is set only when log_min_duration is positive.
> > Additional opinions on this matter are welcome.
>
> I understand your point at last. :)
>
> You mean that ...
> Log_autovacuum_min_duration assumes a role of VACOPT_VERBOSE.
> Even if this parameter never use currently for manual vacuum,
> log_autovacuum_min_duration should be set zero(anytime output)
> when we executes "VACUUM(or ANALYZE) VERBOSE".
> Is my understanding correct? If so,it sounds logical.
>

Yup, that's my opinion. Now I don't know if people would mind to remove
VACOPT_VERBOSE and replace the control it does by log_min_duration in
VacuumStmt. At least both things are overlapping, and log_min_duration
offers more options than the plain VACOPT_VERBOSE.

> If we can abolish VERBOSE option,
> I think it's ideal that we will prepare a new parameter like
> a log_min_duration_vacuum(and log_min_duration_analyze) which
> integrating "VERBOSE feature" and "log_autovacuum_min_duration".
>

What I think you are proposing here is a VERBOSE option that hypothetically
gets activated if a manual VACUUM takes more than a certain amount
specified by those parameters. I doubt this would be useful. In any case
this is unrelated to this patch.
--
Michael