From: Alvaro Herrera <alvherre@alvh.no-ip.org>
To: Alexander Alexander <alexander.berezin3000@gmail.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>
Cc: pgsql-bugs@lists.postgresql.org
Subject: Re: BUG #18477: A specific SQL query with "ORDER BY ... NULLS FIRST" is performing poorly if an ordering column is n
Date: Fri, 24 May 2024 12:03:42 +0200
Message-ID: <202405241003.uxtpwvtwcods@alvherre.pgsql> (raw)
In-Reply-To: <CA+AiShyGQoZfS6NvCfZ6xz1kTm_Sei3DtreXkNhRr5yd8LacVQ@mail.gmail.com>
On 2024-May-24, Alexander Alexander wrote:
> Additionally, as you mentioned, the default index is created with NULLS
> LAST, but in this case, the column is non-nullable, making NULLS LAST
> unnecessary as well.
But the NOT NULL constraint could be dropped at any minute, so the
system needs to know where NULLs would go if that were to happen.
--
Álvaro Herrera PostgreSQL Developer — https://www.EnterpriseDB.com/
"Los dioses no protegen a los insensatos. Éstos reciben protección de
otros insensatos mejor dotados" (Luis Wu, Mundo Anillo)
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To: pgsql-bugs@postgresql.org
Cc: alvherre@alvh.no-ip.org, alexander.berezin3000@gmail.com, tgl@sss.pgh.pa.us, pgsql-bugs@lists.postgresql.org
Subject: Re: BUG #18477: A specific SQL query with "ORDER BY ... NULLS FIRST" is performing poorly if an ordering column is n
In-Reply-To: <202405241003.uxtpwvtwcods@alvherre.pgsql>
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