Message-ID: <24f01200b651ff87311ae0f46b99eaf91fc3ec43.camel@cybertec.at>
Subject: Re: create table explicitly mention that unique|primary key
 constraint will create an
From: Laurenz Albe <laurenz.albe@cybertec.at>
To: jian he <jian.universality@gmail.com>, pgsql-docs@lists.postgresql.org
Date: Mon, 27 Nov 2023 03:30:28 +0100
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On Mon, 2023-11-27 at 08:00 +0800, jian he wrote:
> Hi. minor doc issue.
> create table s1(a int, constraint s2 PRIMARY key (a));
> create table s2(a int);
> ERROR:  relation "s2" already exists
>=20
> https://www.postgresql.org/docs/current/sql-createtable.html#SQL-CREATETA=
BLE-PARMS-UNIQUE
> maybe for the following 2 sentence
> "Adding a unique constraint will automatically create a unique btree
> index on the column or group of columns used in the constraint."
> "Adding a PRIMARY KEY constraint will automatically create a unique
> btree index on the column or group of columns used in the constraint."
>=20
> maybe we can mention that: the unique btree index name will be the
> constraint name.
> also is "a unique" or "an unique"?

It would be "a unique", because "unique" is pronounced "juneek", which
does not start with a vowel.

> I personally thought this part is obscure.

True; I don't find it documented that all objects in pg_class share a
namespace and that constraints are implemented by indexes of the same
name.  But I think that the first part is a property of schemas and had
better be documented there.

What do you think of the attached patch?

Yours,
Laurenz Albe

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