Message-ID: <6f76cd51846f0a8f02df91cc252a7ebcf8c6186f.camel@cybertec.at>
Subject: Re: Nulls Not Distinct in Unique Indexes secton
From: Laurenz Albe <laurenz.albe@cybertec.at>
To: Kirk Parker <khp@equatoria.us>, pgsql-docs@lists.postgresql.org
Date: Thu, 16 Mar 2023 20:48:58 +0100
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On Tue, 2023-03-14 at 08:24 -0700, Kirk Parker wrote:
> The Unique Indexes section (https://www.postgresql.org/docs/15/indexes-un=
ique.html)
> does not mention the new NULLS [ NOT ] DISTINCT capability of indexes
> (https://www.postgresql.org/docs/15/sql-createindex.html), and it probabl=
y should.
>=20
> Specifically, it has the exact wording from previous versions (emphasis a=
dded):
>=20
> =C2=A0 =C2=A0 When an index is declared unique, multiple table
> =C2=A0 =C2=A0 rows with equal indexed values are not allowed.
> =C2=A0 =C2=A0 *Null values are not considered equal*.=20
>=20
> We should consider adding "unless the NULLS NOT DISTINCT clause is used w=
hen
> creating the index", or something to that effect.

+1

Here is a patch for that.

Yours,
Laurenz Albe

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