Re: reloption to prevent VACUUM from truncating empty pages at the end of relation

On Mon, Apr 8, 2019 at 12:22 PM Fujii Masao <masao(dot)fujii(at)gmail(dot)com> wrote:
>
> On Mon, Apr 8, 2019 at 5:30 PM Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com> wrote:
> >
> > On Mon, Apr 8, 2019 at 5:15 PM Fujii Masao <masao(dot)fujii(at)gmail(dot)com> wrote:
> > >
> > > On Mon, Apr 8, 2019 at 3:58 PM Julien Rouhaud <rjuju123(at)gmail(dot)com> wrote:
> > > >
> > > > On Mon, Apr 8, 2019 at 8:01 AM Fujii Masao <masao(dot)fujii(at)gmail(dot)com> wrote:
> > > > >
> > > > > 2019年4月8日(月) 14:22 Tsunakawa, Takayuki <tsunakawa(dot)takay(at)jp(dot)fujitsu(dot)com>:
> > > > >>
> > > > >> From: Alvaro Herrera [mailto:alvherre(at)2ndquadrant(dot)com]
> > > > >> > "vacuum_truncate" gets my vote too.
> > > > >>
> > > > >> +1
> > > > >
> > > > >
> > > > > +1
> > > > > ISTM that we have small consensus to
> > > > > use "vacuum_truncate".
> > > >
> > > > I'm also fine with this name, and I also saw reports that this option
> > > > is already needed in some production workload, as Andres explained.
> > >
> > > OK, so I pushed the "vacuum_truncate" version of the patch.
> >
> > Thank you!
> >
> > "TRUNCATE" option for vacuum command should be added to the open items?
>
> Yes, I think.
> Attached is the patch which adds TRUNCATE option into VACUUM.

Thanks.

I just reviewed the patch, it works as expected, no special comment on the code.

Minor nitpicking:

- lock on the table.
+ lock on the table. The <literal>TRUNCATE</literal> parameter
+ to <xref linkend="sql-vacuum"/>, if specified, overrides the value
+ of this option.

maybe "parameter of" instead of "parameter to"?