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not in(subselect) in 8.4

From: Grzegorz Jaśkiewicz <gryzman(at)gmail(dot)com>
To: "pgsql-performance(at)postgresql(dot)org" <pgsql-performance(at)postgresql(dot)org>
Subject: not in(subselect) in 8.4
Date: 2009-02-20 09:56:05
Message-ID: 2f4958ff0902200156y7c38f698gcf810032cf8dd8c0@mail.gmail.com (view raw or flat)
Thread:
Lists: pgsql-performance
Just as a question to Tom and team,
I saw a post a bit ago, about plans for 8.4, and Tom said it is very
likely that 8.4 will rewrite subselects into left joins, is it still
in plans?

I mean query like:
select id from foo where id not in ( select id from bar);
into:

select f.id from foo f left join bar b on f.id=b.id where b.id is null;

the latter is most often much much faster on 8.1-8.3;

thanks.

-- 
GJ

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