Re: Finding uniques across a big join - Mailing list pgsql-general

From Bruno Wolff III
Subject Re: Finding uniques across a big join
Date
Msg-id 20051201053119.GA19705@wolff.to
Whole thread Raw
In response to Re: Finding uniques across a big join  ("John D. Burger" <john@mitre.org>)
Responses Re: Finding uniques across a big join
List pgsql-general
On Wed, Nov 30, 2005 at 20:44:30 -0500,
  "John D. Burger" <john@mitre.org> wrote:
>
> That changes the semantics of what I want.  If I group by personID
> above, then every FOUR-way combo is of course unique.  What I'd like to
> do is group by the three attributes, and select for personID as well.
> But of course you can't select for columns you haven't grouped by.

Assuming that personID is an ordered type, you can select max(personID)
in the GROUP BY and save the join at the end.

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