Re: Removing Inner Joins - Mailing list pgsql-hackers

From Atri Sharma
Subject Re: Removing Inner Joins
Date
Msg-id CAOeZVifdRMhw10wam9bTp83qJ-=UmX3RqmqogRJ-6TUTGvmr9g@mail.gmail.com
Whole thread Raw
In response to Re: Removing Inner Joins  (Hannu Krosing <hannu@2ndQuadrant.com>)
List pgsql-hackers
On Wed, Jul 10, 2013 at 1:11 PM, Hannu Krosing <hannu@2ndquadrant.com> wrote:
> On 07/10/2013 09:18 AM, Atri Sharma wrote:
>>> Can you please post an example of such a join removal? I mean a query before
>>> and after the removal. Thanks,
>> Courtesy Robert Haas:
>>
>> SELECT foo.x, foo.y, foo.z FROM foo WHERE foo.x = bar.x
>>
>> Conditions:
>>
>> 1) foo.x is not null.
> I guess that this is also not needed. you can just remove rows where
>
> foo.x is null
>
> That is, replace the join with "foo.x is not null"

Yeah, sounds good. We should explore it further.

Regards,

Atri


--
Regards,

Atri
l'apprenant



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