I'm a newbie in this topic of Ruby programming, I would like to know the main diferences about Ruby and PHP.

Which one has more features?
Which one is more fast to learn?
Which one is more fast? Or prevent overload of server?
Which DB works for Ruby?
What are the main advantages to all the rest of the web languages?

Have anyone installed Ruby and PHP in your server and can both run great on a normal server?

Anything you want to say about php or ruby I would like to know, if this new language will be a great deal to learn.

Thanks in advance!