2010/3/19 Olav Mørkrid
> Dear MySQL forum.
>
> I have performance problems when using "left join x" combined with
> "where x.y is null", in particularily when combining three tables this
> way.
>
With a left join, particularly when you're using *is (not) null*, you can't
use index selecting on y
Dear MySQL forum.
I have performance problems when using "left join x" combined with
"where x.y is null", in particularily when combining three tables this
way.
Please contact me by e-mail if you are familiar with these issues and
know how to eliminate slow queries.
I would really appreciate you
