Outer join with where conditions

From: Michał Otroszczenko <michal(dot)otroszczenko(at)gmail(dot)com>
To: pgsql-general(at)postgresql(dot)org
Subject: Outer join with where conditions
Date: 2005-11-14 13:45:22
Message-ID: 446305c00511140545p1fbfa57bl@mail.gmail.com
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Hello,

I wonder If I could move additional join condition from ON part of
query to where part.

For example instead of:

SELECT * FROM
booking_load AS bload
LEFT OUTER JOIN dict_load_type_tsl AS load_tsl ON (
load_tsl.dict_load_type_id = bload.dict_load_type_id
AND load_tsl.dict_language_id = 'EN' ))

Could I write:

SELECT * FROM
booking_load AS bload
LEFT OUTER JOIN dict_load_type_tsl AS load_tsl USING (dict_load_type_id)
WHERE
load_tsl.dict_language_id = 'EN'

I thought that second query could be more 'optimizable', but gave no results.
Where is the problem ?

Best regards,
Michal

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