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From: Shin Berg <sjh910805@gmail.com>
Date: Mon, 16 Mar 2026 10:15:24 +0900
Message-ID: 
 <CACSdjfN6ydot=nibVF5__-Q7H7AFUG5r96EYbV9SWnM4VBmVyg@mail.gmail.com>
Subject: Re: Inconsistency in owner assignment between INDEX and STATISTICS
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Amit Khandekar <amitdkhan.pg@gmail.com>,
 pgsql-hackers@lists.postgresql.org
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Thank you for the additional context, Tom. That makes the design intent
much clearer.
Cross-table statistics, if realized, would be a significant improvement for
join cardinality estimation; looking forward to seeing that develop.

Regards,
Joshua Shin

On Mon, Mar 16, 2026 at 5:09=E2=80=AFAM Tom Lane <tgl@sss.pgh.pa.us> wrote:

> Shin Berg <sjh910805@gmail.com> writes:
> > Thank you for the detailed feedback, Amit.
> > You're right on both points. I had been comparing STATISTICS against
> INDEX
> > and treating the difference as an inconsistency, but as you point out,
> > INDEX ownership is special =E2=80=94 it's tied to the table and intenti=
onally not
> > user-adjustable. STATISTICS follows the same ownership model as VIEW (t=
he
> > creator becomes the owner), which is consistent and by design.
>
> One point that was not mentioned is that while indexes are necessarily
> tied to a single table, statistics objects might not always be.  The
> long-term hope is to allow statistics on cross-table combinations of
> columns, which is why the syntax was intentionally set up to look like
> SELECT.  So, just like views, it's reasonable to give them independent
> ownership.
>
>                         regards, tom lane
>

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<div dir=3D"ltr">Thank you for the additional context, Tom. That makes the =
design intent much clearer. <br>Cross-table statistics, if realized, would =
be a significant improvement for join cardinality estimation; looking forwa=
rd to seeing that develop.<br><br>Regards,<br>Joshua Shin</div><br><div cla=
ss=3D"gmail_quote gmail_quote_container"><div dir=3D"ltr" class=3D"gmail_at=
tr">On Mon, Mar 16, 2026 at 5:09=E2=80=AFAM Tom Lane &lt;<a href=3D"mailto:=
tgl@sss.pgh.pa.us">tgl@sss.pgh.pa.us</a>&gt; wrote:<br></div><blockquote cl=
ass=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid=
 rgb(204,204,204);padding-left:1ex">Shin Berg &lt;<a href=3D"mailto:sjh9108=
05@gmail.com" target=3D"_blank">sjh910805@gmail.com</a>&gt; writes:<br>
&gt; Thank you for the detailed feedback, Amit.<br>
&gt; You&#39;re right on both points. I had been comparing STATISTICS again=
st INDEX<br>
&gt; and treating the difference as an inconsistency, but as you point out,=
<br>
&gt; INDEX ownership is special =E2=80=94 it&#39;s tied to the table and in=
tentionally not<br>
&gt; user-adjustable. STATISTICS follows the same ownership model as VIEW (=
the<br>
&gt; creator becomes the owner), which is consistent and by design.<br>
<br>
One point that was not mentioned is that while indexes are necessarily<br>
tied to a single table, statistics objects might not always be.=C2=A0 The<b=
r>
long-term hope is to allow statistics on cross-table combinations of<br>
columns, which is why the syntax was intentionally set up to look like<br>
SELECT.=C2=A0 So, just like views, it&#39;s reasonable to give them indepen=
dent<br>
ownership.<br>
<br>
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=
=A0 =C2=A0 regards, tom lane<br>
</blockquote></div>

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