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Date: Tue, 24 Dec 2019 19:13:32 +0100 (CET)
From: Fabien COELHO <coelho@cri.ensmp.fr>
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To: Alvaro Herrera <alvherre@2ndquadrant.com>
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    Peter Eisentraut <peter.eisentraut@2ndquadrant.com>,
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Subject: Re: Allow an alias to be attached directly to a JOIN ... USING
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On Tue, 17 Sep 2019, Alvaro Herrera wrote:

>> Indeed, that seems like a problem, and it's a good question.  You can
>> see this on unpatched master with SELECT x.filler FROM
>> (pgbench_tellers AS t JOIN b USING (bid)) AS x.
>
> I'm not sure I understand why that problem is a blocker for this patch.

As discussed on another thread,

     https://www.postgresql.org/message-id/flat/2aa57950-b1d7-e9b6-0770-fa592d565dda@2ndquadrant.com

the patch does not conform to spec

   SQL:2016 Part 2 Foundation Section 7.10 <joined table>

Basically "x" is expected to include *ONLY* joined attributes with USING, 
i.e. above only x.bid should exists, and per-table aliases are expected to 
still work for other attributes.

ISTM that this patch could be "returned with feedback".

-- 
Fabien.