Re: [PG13] Planning (time + buffers) data structure in explain plan (format text)

On Fri, Aug 7, 2020 at 3:51 PM Pierre Giraud <pierre(dot)giraud(at)dalibo(dot)com> wrote:
>
> Le 07/08/2020 à 14:52, Julien Rouhaud a écrit :
> > Hi,
> >
> > On Fri, Aug 7, 2020 at 2:30 PM Pierre Giraud <pierre(dot)giraud(at)dalibo(dot)com> wrote:
> >>
> >> Hi all,
> >>
> >> As far as I understand, in the upcoming version 13, information about
> >> buffers used during planning is now available in the explain plan.
> >
> > Indeed.
> >
> >> […]
> >> Planning Time: 0.203 ms
> >> Buffers: shared hit=14
> >> […]
> >>
> >> In the JSON format, the data structure is a bit different:
> >>
> >> […]
> >> "Planning": {
> >> "Planning Time": 0.533,
> >> "Shared Hit Blocks": 14,
> >> "Shared Read Blocks": 0,
> >> "Shared Dirtied Blocks": 0,
> >> "Shared Written Blocks": 0,
> >> "Local Hit Blocks": 0,
> >> "Local Read Blocks": 0,
> >> "Local Dirtied Blocks": 0,
> >> "Local Written Blocks": 0,
> >> "Temp Read Blocks": 0,
> >> "Temp Written Blocks": 0
> >> },
> >> […]
> >>
> >> For a matter of consistency, I wonder if it would be possible to format
> >> it like the following:
> >>
> >> […]
> >> Planning:
> >> Planning Time: 0.203 ms
> >> Buffers: shared hit=14
> >> […]
> >
> > I agree that this output looks more consistent with other output,
> > including JIT as you mentioned. I'll send a patch for that if there's
> > no objection.
>
> Thanks a lot!
>
> >
> > Out of curiosity, is the current text output actually harder to parse
> > than the one you're suggesting?
> >
>
> I don't want to speak in the name of developers of others parsing tools
> but this should not require a lot of work to parse the output I'm proposing.
> It would be nice to have their opinion though, especially Hubert depesz
> Lubaczewski's since he already integrated the change:
> https://gitlab.com/depesz/Pg--Explain/-/commit/4a760136ee69ee4929625d4e4022f79ac60b763f
>
> However, as far as I know, he's not doing anything with the buffers
> information with the "Planning" section yet.
>
> To answer your question, I think that the new output would make the
> parser a little bit easier to write because it would make things a bit
> clearer (ie. more separated) so less prone to errors.

Adding depesz.