[prev in list] [next in list] [prev in thread] [next in thread]
List: pgsql-hackers
Subject: Re: list of extended statistics on psql
From: Pavel Stehule <pavel.stehule () gmail ! com>
Date: 2020-08-31 18:38:11
Message-ID: CAFj8pRDsiGozdoeqHC6d8disaY62Zihw5hL3dUHeFaDjyZAxNw () mail ! gmail ! com
[Download RAW message or body]
po 31. 8. 2020 v 18:32 odes=C3=ADlatel Tomas Vondra <tomas.vondra@2ndquadra=
nt.com>
napsal:
> On Mon, Aug 31, 2020 at 12:18:09PM -0400, Alvaro Herrera wrote:
> >On 2020-Aug-31, Tomas Vondra wrote:
> >
> >> I wonder if trying to list info about all stats from the statistics
> >> object in a single line is necessary. Maybe we should split the info
> >> into one line per statistics, so for example
> >>
> >> CREATE STATISTICS s (mcv, ndistinct, dependencies) ON ...
> >>
> >> would result in three lines in the \dX output. The statistics name wou=
ld
> >> identify which lines belong together, but other than that the pieces a=
re
> >> mostly independent.
> >
> >Yeah, that's what I'm suggesting. I don't think we need to repeat the
> >name/definition for each line though.
> >
> >It might be useful to know how does pspg show a single entry that's
> >split in three lines, though.
> >
>
> Ah, I didn't realize you're proposing that - I assumed it's broken
> simply to make it readable, or something like that. I think the lines
> are mostly independent, so I'd suggest to include the name of the object
> on each line. The question is whether this independence will remain true
> in the future - for example histograms would be built only on data not
> represented by the MCV list, so there's a close dependency there.
>
> Not sure about pspg, and I'm not sure it matters too much.
>
pspg almost ignores multiline rows - the horizontal cursor is one row every
time. There is only one use case where pspg detects multiline rows - sorts,
and pspg ensures correct content for multiline rows displayed in different
(than input) order.
Regards
Pavel
>
> regards
>
> --
> Tomas Vondra http://www.2ndQuadrant.com
> PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
>
[Attachment #3 (text/html)]
<div dir="ltr"><div dir="ltr"><br></div><br><div class="gmail_quote"><div dir="ltr" \
class="gmail_attr">po 31. 8. 2020 v 18:32 odesÃlatel Tomas Vondra <<a \
href="mailto:tomas.vondra@2ndquadrant.com">tomas.vondra@2ndquadrant.com</a>> \
napsal:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px \
0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">On Mon, Aug 31, 2020 \
at 12:18:09PM -0400, Alvaro Herrera wrote:<br> >On 2020-Aug-31, Tomas Vondra \
wrote:<br> ><br>
>> I wonder if trying to list info about all stats from the statistics<br>
>> object in a single line is necessary. Maybe we should split the info<br>
>> into one line per statistics, so for example<br>
>><br>
>> CREATE STATISTICS s (mcv, ndistinct, dependencies) ON ...<br>
>><br>
>> would result in three lines in the \dX output. The statistics name would<br>
>> identify which lines belong together, but other than that the pieces are<br>
>> mostly independent.<br>
><br>
>Yeah, that's what I'm suggesting. I don't think we need to repeat \
the<br> >name/definition for each line though.<br>
><br>
>It might be useful to know how does pspg show a single entry that's<br>
>split in three lines, though.<br>
><br>
<br>
Ah, I didn't realize you're proposing that - I assumed it's broken<br>
simply to make it readable, or something like that. I think the lines<br>
are mostly independent, so I'd suggest to include the name of the object<br>
on each line. The question is whether this independence will remain true<br>
in the future - for example histograms would be built only on data not<br>
represented by the MCV list, so there's a close dependency there.<br>
<br>
Not sure about pspg, and I'm not sure it matters too \
much.<br></blockquote><div><br></div><div>pspg almost ignores multiline rows - the \
horizontal cursor is one row every time. There is only one use case where pspg \
detects multiline rows - sorts, and pspg ensures correct content for multiline rows \
displayed in different (than input) \
order.</div><div><br></div><div>Regards</div><div><br></div><div>Pavel<br></div><div> \
<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px \
0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"> <br>
<br>
regards<br>
<br>
-- <br>
Tomas Vondra <a href="http://www.2ndQuadrant.com" \
rel="noreferrer" target="_blank">http://www.2ndQuadrant.com</a><br> PostgreSQL \
Development, 24x7 Support, Remote DBA, Training & Services<br> \
</blockquote></div></div>
[prev in list] [next in list] [prev in thread] [next in thread]
Configure |
About |
News |
Add a list |
Sponsored by KoreLogic