Re: Re: [COMMITTERS] pgsql: Recognize functional dependency on primary keys. - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Re: [COMMITTERS] pgsql: Recognize functional dependency on primary keys.
Date
Msg-id 29130.1281757076@sss.pgh.pa.us
Whole thread Raw
In response to Re: Re: [COMMITTERS] pgsql: Recognize functional dependency on primary keys.  (Bruce Momjian <bruce@momjian.us>)
Responses Re: Re: [COMMITTERS] pgsql: Recognize functional dependency on primary keys.  (Bruce Momjian <bruce@momjian.us>)
List pgsql-hackers
Bruce Momjian <bruce@momjian.us> writes:
> Tom Lane wrote:
>> I'm not sure whether there is any clear rule for what rows you get when
>> grouping by a non-PK column in mysql, but it'll let you do it.

> I understand this.  The issue is how many people who complained about
> our GROUP BY behavior were grouping by something that was a primary key,
> and how many were not using a primary key?  The former will no longer
> complain.

No doubt, but the TODO entry you removed is still 100% accurately
worded, and what's more the archive entry it links to clearly describes
exactly the point at issue, namely that grouping by a PK *isn't*
indeterminate.  You were wrong to remove it.
        regards, tom lane


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