Originally Posted by Highway of Life

Have you run benchmarks against them? how do you know?
Running them side-by-side, you may not notice a difference, in-fact, you probably won't.
They may slow down by 0.01 seconds, which may seem insignificant, but that will make a big difference the more queries you have and the more traffic you have on your site that would cause these queries to run.
A savings of 0.01 seconds is significant on my sites. But regardless, it’s a good idea to use correct practices, and xenon is correct regarding the usage of aliases.
Aliases would be needed on multiple table queries, but are not needed when querying a single table. :)

It’s not a *big* deal, but it’s still good practice. ;)