Re: nested select query failing

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От Stephan Szabo
Тема Re: nested select query failing
Дата
Msg-id 20030515075032.B60859-100000@megazone23.bigpanda.com
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Ответ на Re: nested select query failing  (SZUCS Gábor <surrano@mailbox.hu>)
Список pgsql-performance
On Thu, 15 May 2003, [iso-8859-1] SZUCS G�bor wrote:

> Basically, is it true that IN's can be converted to RIGHT JOIN's quite
> simply? Is it always worth?

I'm not sure you want to convert to an outer join (since you want to throw
away the rows on either side that don't match in an IN).  You also have to
be careful not to get duplicate entries from what was the subquery.

As for whether it's worth doing, in 7.3 and earlier, almost
certainly, in 7.4 almost certainly not. :)




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