On Fri, 21 Mar 2014 06:54:21 +0100, Thomas Beckmann
<thomas.beckmann@...> wrote:

> Thank you for your answer, Mark,
>
> my friend and collegue Frank (fsg) and I kept in mind, that at the prior
> to the last FB-conference, we listend to an optimization talk of one of
> the core devs (it must have been Dimitry ;-) ) and remembered that:
>
> - engine does not reorder joins for optimization purpose if left join
> and straight join get mixed
> - engine evaluates join before left join.
>
> This was, what made me assue, the expression would be evaluated like the
> braced version. I did not check SQL standard definition yet, but it
> seemed somewhat natural to me...

AFAIK those ordering rules only apply if you have multiple joins joining
to the same table, in this case you define a string of joins from and
therefor they are evaluated in order unless you apply braces.

Mark