Re: pgsql: Improve autovacuum logging for aggressive andanti-wraparound ru

On Tue, Sep 25, 2018 at 6:11 AM Alvaro Herrera <alvherre@2ndquadrant.com> wrote:
>
> On 2018-Sep-24, Sergei Kornilov wrote:
>
> > Hi
> >
> > > An autovacuum can't be just aggressive; it's either anti-wraparound or normal.
> > But autovacuum _can_ be aggressive and not anti-wraparound.
> > I build current master and can see 3 different line types:
> > 2018-09-24 23:47:31.500 MSK 27939 @ from  [vxid:4/272032 txid:0] [] LOG:  automatic aggressive vacuum of table
"postgres.public.foo":index scans: 0
 
> > 2018-09-24 23:49:27.892 MSK 28333 @ from  [vxid:4/284297 txid:0] [] LOG:  automatic aggressive vacuum to prevent
wraparoundof table "postgres.public.foo": index scans: 0
 
> > 2018-09-24 23:49:29.093 MSK 28337 @ from  [vxid:4/284412 txid:0] [] LOG:  automatic vacuum of table
"postgres.public.foo":index scans: 0
 
>
> Exactly.
>
> It cannot be anti-wraparound and not aggressive, which is the line type
> not shown.
>
> "Aggressive" means it scans all pages; "anti-wraparound" means it does
> not let itself be cancelled because of another process waiting for a
> lock on the table.
>

I agree. Can we fix this simply by the attached patch?

Regards,

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