Re: [PG13] Planning (time + buffers) data structure in explain plan (format text) - Mailing list pgsql-hackers

From Julien Rouhaud
Subject Re: [PG13] Planning (time + buffers) data structure in explain plan (format text)
Date
Msg-id CAOBaU_aQLnaDs4q=ijVPWocWe5vv82VOU0Ypc+6WuVTwi+cb1w@mail.gmail.com
Whole thread Raw
In response to Re: [PG13] Planning (time + buffers) data structure in explain plan (format text)  (Pierre Giraud <pierre.giraud@dalibo.com>)
List pgsql-hackers
On Fri, Aug 7, 2020 at 3:51 PM Pierre Giraud <pierre.giraud@dalibo.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.giraud@dalibo.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.



pgsql-hackers by date:

Previous
From: Asim Praveen
Date:
Subject: Re: recovering from "found xmin ... from before relfrozenxid ..."
Next
From: Magnus Hagander
Date:
Subject: Re: run pgindent on a regular basis / scripted manner