Re: pgsql: Improve autovacuum logging for aggressive and anti-wraparound ru

On Tue, Oct 2, 2018 at 9:11 AM Michael Paquier <michael@paquier.xyz> wrote:
>
> On Fri, Sep 28, 2018 at 01:53:14PM +0900, Masahiko Sawada wrote:
> > I agree. Can we fix this simply by the attached patch?
>
> Thanks for sending a patch.
>
> +    /* autovacuum cannot be anti-wraparound and not aggressive vacuum */
> +    Assert(aggressive);
> +    msgfmt = _("automatic aggressive vacuum to prevent wraparound of table \"%s.%s.%s\": index scans: %d\n");
>
> While adding this comment in lazy_vacuum_rel() is adapted, I think that
> we ought to make the assertion check more aggressive by not having it
> depend on if log_min_duration is set or not. So why not moving that to
> a place a bit higher, where aggressive gets defined?

Since there is no place where checks params->is_wraparound we will
have to do something like;

if (params->is_wraparound)
    Assert(aggressive);

Or you meant the following?

Assert(params->is_wraparound ? aggressive : true);

I'm not sure both styles would be appropriate style in the postgres
code so I would rather add elog(ERROR) instead. Thought?

Regards,

--
Masahiko Sawada
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center