Re: Note new NULLS NOT DISTINCT on unique index tutorial page - Mailing list pgsql-hackers

From David Rowley
Subject Re: Note new NULLS NOT DISTINCT on unique index tutorial page
Date
Msg-id CAApHDvrhZnq2hQ0PJXhyAUxpidQ9xfGrUSHXrLo-ZwbxqhD8JQ@mail.gmail.com
Whole thread Raw
In response to Re: Note new NULLS NOT DISTINCT on unique index tutorial page  (Corey Huinker <corey.huinker@gmail.com>)
List pgsql-hackers
On Tue, 18 Apr 2023 at 05:01, Corey Huinker <corey.huinker@gmail.com> wrote:
> I'm ok with the wording as-is, but perhaps we can phrase it as "distinct" vs "not equal", thus leaning into the
syntaxa bit:
 
>
> By default, null values in a unique column are considered distinct, allowing multiple nulls in the column.
>
>
> or maybe
>
> By default, null values in a unique column are considered <literal>DISTINCT</literal>, allowing multiple nulls in the
column.>

I acknowledge your input, but I didn't think either of these was an
improvement over what David suggested.  I understand that many people
will know that "SELECT DISTINCT" and "WHERE x IS NOT DISTINCT FROM y"
means treat NULLs equally, but I don't think we should expect the
reader here to know that's what we're talking about.   In any case,
we're talking about existing wording here, not something David is
adding.

David



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