Re: DISTINCT vs. GROUP BY

Jim C. Nasby wrote:
> On Mon, Sep 19, 2005 at 10:16:36PM -0400, Bruce Momjian wrote:
> >  
> > Added to TODO:
> > 
> >     * Allow DISTINCT to use hashing like GROUP BY
> 
> 3 lines above we have...
> Consider using hash buckets to do DISTINCT, rather than sorting
> This would be beneficial when there are few distinct values. 

OK, I have merged these items into one.

> 
> Can you add
> http://archives.postgresql.org/pgsql-hackers/2005-09/msg00810.php? All I
> could find on the other TODO was
> http://archives.postgresql.org/pgsql-committers/2004-09/msg00028.php,
> which doesn't help much...

What do these URL's have that the current TODO does not?

* Consider using hash buckets to do DISTINCT, rather than sorting
 This would be beneficial when there are few distinct values.  This is already used by GROUP BY.

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