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Date: Mon, 27 Sep 2010 17:54:18 +0100
From: Tarlika Elisabeth Schmitz <postgresql@numerixtechnology.de>
To: pgsql-sql@postgresql.org
Subject: Re: identifying duplicates in table with redundancies
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On Fri, 24 Sep 2010 18:12:18 +0100
Oliver d'Azevedo Christina <oliveiros.cristina@gmail.com> wrote:

>>> SELECT DISTINCT trainer_id,trainer_name
>>> FROM (
>>> SELECT trainer_name   -- The field you want to test for duplicates
>>> FROM (
>>> SELECT DISTINCT "trainer_id","trainer_name"
>>> FROM student
>>> ) x
>>> GROUP BY "trainer_name"    -- the field you want to test for  
>>> duplicates
>>> HAVING (COUNT(*) > 1)
>>> ) z
>>> NATURAL JOIN student y  



What indices would you recommend for this operation?

-- 

Best Regards,
Tarlika Elisabeth Schmitz