Re: A MySQL Question
| From: | Ashley Sheridan | Date: | Mon, 08 Dec 2008 23:34:59 +0000 |
| Subject: | Re: A MySQL Question | ||
| References: | 1 | Groups: | php.general |
| Request: | Send a blank email to php-general+get-284331@lists.php.net to get a copy of this message | ||
On Mon, 2008-12-08 at 23:23 +0000, ceo@l-i-e.com wrote:
> Presumable, the EXISTS sub-query can be optimized sometimes to just stop processing the
> sub-query and kick things back out to the outer query.
>
>
>
> IN has to process them all and find them all.
>
>
>
Don't forget the special case use as well:
IF NOT EXISTS
universe THEN bigbang()
Ash
www.ashleysheridan.co.uk