Re: [HACKERS] Re: [HACKERS] GSoC 2015 proposal: Improve the performance of “ALTER TABLE .. SET LOGGED / UNLOGGED” statement

On Thu, Jul 9, 2015 at 10:56 AM, Andres Freund <andres(at)anarazel(dot)de> wrote:
>
> On 2015-07-09 10:39:35 -0300, Fabrízio de Royes Mello wrote:
> > If the "wal_level=minimal" we don't need to force the wal log of the
> > contents. If the "wal_level != minimal" we need just to xlog all the
pages,
> > but in both cases we don't need the extra job to create a new datafiles
and
> > copy the contents between them. So we'll improve performance, or am I
> > missing something?
>
> Sure. It'll be a bit faster. I just don't see the peformance increase in
> not that common situations being worth the price we'll pay in
> development, code review, debugging and then maintaining some nontrivial
> code. If this were likely to be a 15 line patch, I'd think differently.

Well, this will not be a 15 line patch, but I'll try to simplify as much as
possible.

Regards,

--
Fabrízio de Royes Mello
Consultoria/Coaching PostgreSQL
>> Timbira: http://www.timbira.com.br
>> Blog: http://fabriziomello.github.io
>> Linkedin: http://br.linkedin.com/in/fabriziomello
>> Twitter: http://twitter.com/fabriziomello
>> Github: http://github.com/fabriziomello