From: Adarsh Sharma <adarsh.sharma@orkash.com>
To: Vitalii Tymchyshyn <tivv00@gmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Re-Reason of Slowness of Query
Date: Wed, 23 Mar 2011 15:49:18 +0530
Message-ID: <4D89C926.8050009@orkash.com> (raw)
In-Reply-To: <4D89C778.6050805@gmail.com>
References: <4D89BABF.4080806@orkash.com>
<4D89BCD6.6040604@gmail.com>
<4D89C704.5080603@orkash.com>
<4D89C778.6050805@gmail.com>
Vitalii Tymchyshyn wrote:
> 23.03.11 12:10, Adarsh Sharma ???????(??):
>> I just want to retrieve that id 's from page_content which do not
>> have any entry in clause2 table.
>>
> Then
> select distinct(p.crawled_page_id) from page_content p
> where NOT EXISTS (select 1 from clause2 c where c.source_id =
> p.crawled_page_id);
> is correct query.
>
I can't understand how* select 1 from clause2 c where c.source_id =
p.crawled_page_id works too, *i get my output .
What is the significance of 1 here.
Thanks , Adarsh
**
> Best regards, Vitalii Tymchyshyn.
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-performance@postgresql.org
Cc: adarsh.sharma@orkash.com, tivv00@gmail.com
Subject: Re: Re-Reason of Slowness of Query
In-Reply-To: <4D89C926.8050009@orkash.com>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox