1346Re: 1344MYSQL IN clause is expensive?

Thanks Dennis

I have one more doubt. Is that join will not be too heavy bcoz
actually i have shown a sample query, but in real we already have some
3-4 tables joined and only for this if we again join then it will be
expensive. Pls comment on this.

On Dec 10, 7:17 pm, Dennis Benedetto <dbened...@hotmail.com> wrote:
> yes it is, it is better to do a left join on the table and exclude in the where clause where one of the fields is not null
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> > Date: Wed, 9 Dec 2009 23:20:19 -0800
> > Subject: 1344MYSQL IN clause is expensive?
> > From: natarajanonl...@gmail.com
> > To: it_help_desk@googlegroups.com
>
> > Hi,
>
> > I would like to use SELECT * from users where userid IN(SELECT userid
> > from user_book where availability=1)
>
> > In the above subquery, it can return 1000 of records. Whether this
> > operation is expensive?
>
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Dot Net, VB.NET, C#, ADO.Net, ASP.NET, XML, WML, Ajax, SAP, Ruby, Java, SAP, WAP, WML, PHP, MYSQL, ASP, SQL, HTML, DHTML CSS, Flash, Flex, IT Jobs , Freelancer Projects & many more

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