I am considering using AWS's SimpleDB instead of my current MySQL database.
My reasons for considering the change are:
My website is one in which the database is growing very large in size, very quickly.
Using SimpleDB will allow me to have a flexible and easily expanding database, paying for what I use at the current time.
Using SimpleDB allows me to have a database which is not part of my hosting provider, making changing hosting providers a more simple process.
Has anyone had any experience with SimpleDB, is it worth the change, and how does it compare to a locally hosted MySQL db?
Also, I am slightly confused as to what AWS means by 'machine hours'? It says that the first 25 'machine hours' per month are free.... is a machine hour using the database for 1 hour? In which case you would incur 24 machine hours per day, every day? Or is it a measure of the usage of the database? So you might only use 20 machine hours in a month?