On 15 Set, 16:17, "J.O. Aho" <u...@example.net> wrote:
> Lo'oris wrote:
> > has a condition such as " WHERE primary_key='$x' ", adding "LIMIT 1"
>
> Here is the official version with some user comments:http://dev.mysql.com/doc/refman/5.0/...imization.html

but it does not talk about primary keys :/