André Hänsel schrieb:
Likely. The mysql optimizer doesn't try to optimize things that you
could write more efficiently by yourself (at least that's what I read
between the lines of the docs and guiding principles of the optimizer
design - I may be wrong).
Try EXPLAIN <sql-statement> for each of the two statements; if the
results are the same, the optimizer will be equally efficient (or
inefficient, as the case may be); if they are different, you most likely
will have performance differences.