Date: Tue, 1 Sep 2020 17:08:25 -0400
From: Alvaro Herrera <alvherre@2ndquadrant.com>
To: Justin Pryzby <pryzby@telsasoft.com>
Cc: gkokolatos@pm.me, pgsql-hackers@postgresql.org,
	Tomas Vondra <tomas.vondra@2ndquadrant.com>,
	Tatsuro Yamada <tatsuro.yamada.tf@nttcom.co.jp>
Subject: Re: v13: show extended stats target in \d
Message-ID: <20200901210825.GA20170@alvherre.pgsql>
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+1 on fixing this, since the ability to change stats target is new in
pg13.

On 2020-Aug-31, Justin Pryzby wrote:

> Maybe it should have a comma, like ", STATISTICS %s"?

It does need some separator.  Maybe a comma is sufficient, but I'm not
sure: that will fail when we add cross-relation stats, because the
FROM clause will have more relations and possibly have commas too.

                                    Table "public.ab1"
 Column |  Type   | Collation | Nullable | Default | Storage | Stats target | Description
--------+---------+-----------+----------+---------+---------+--------------+-------------
 a      | integer |           |          |         | plain   |              |
 b      | integer |           |          |         | plain   |              |
Statistics objects:
    "public"."ab1_a_b_stats" (ndistinct, dependencies, mcv) ON a, b FROM ab1


> Also, now I wonder if CREATE STATISTICS should support some syntax to set the
> initial target.  Like:
> 
> |CREATE STATISTICS abstats ON a,b FROM child.abc_202006 WITH(STATISTICS 111);

Umm, if true (on which I'm not sold), maybe it should appear in the
parenthesized list that currently is just the stats type list:

 |CREATE STATISTICS abstats (STATISTICS 111) ON a,b FROM child.abc_202006;

I'm not really convinced we need this.

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services