Re: list of extended statistics on psql

From: Tatsuro Yamada <tatsuro(dot)yamada(dot)tf(at)nttcom(dot)co(dot)jp>
To: Tomas Vondra <tomas(dot)vondra(at)enterprisedb(dot)com>, Alvaro Herrera <alvherre(at)2ndquadrant(dot)com>
Cc: Tomas Vondra <tomas(dot)vondra(at)2ndquadrant(dot)com>, Michael Paquier <michael(at)paquier(dot)xyz>, Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>, Julien Rouhaud <rjuju123(at)gmail(dot)com>, PostgreSQL Hackers <pgsql-hackers(at)lists(dot)postgresql(dot)org>
Subject: Re: list of extended statistics on psql
Date: 2021-01-07 23:52:02
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On 2021/01/08 0:56, Tomas Vondra wrote:
> On 1/7/21 3:47 PM, Alvaro Herrera wrote:
>> On 2021-Jan-07, Tomas Vondra wrote:
>>> On 1/7/21 1:46 AM, Tatsuro Yamada wrote:
>>>> I overlooked the check for MCV in the logic building query
>>>> because I created the patch as a new feature on PG14.
>>>> I'm not sure whether we should do back patch or not. However, I'll
>>>> add the check on the next patch because it is useful if you decide to
>>>> do the back patch on PG10, 11, 12, and 13.
>>> BTW perhaps a quick look at the other \d commands would show if there are
>>> precedents. I didn't have time for that.
>> Yes, we do promise that new psql works with older servers.
> Yeah, makes sense. That means we need add the check for 12 / MCV.

Ah, I got it.
I fixed the patch to work with older servers to add the checking versions. And I tested \dX command on older servers (PG10 - 13).
These results look fine.

Added the check code to handle pre-PG12. It has not MCV and
This patch is the same as the previous patch (not changed).

Please find the attached files.

>> I wonder the column names added by \dX+ is fine? For example,
>> "Ndistinct_size" and "Dependencies_size". It looks like long names,
>> but acceptable?
> Seems acceptable - I don't have a better idea.

I see, thanks!

Tatsuro Yamada

Attachment Content-Type Size
0001-Add-dX-command-on-psql-with-version-check.patch text/plain 9.3 KB
0002-Add-regression-test-for-dX-on-psql.patch text/plain 9.7 KB

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