Not sure what's your questions. It's too open ended. Many sites are 100% database backend and their speed are pretty fast. If your data doesn't change too often there are many ways of caching like generating static HTML pages off your database, or using some kind of database caching like
Memcache .
Lastly, if you only care about managing the site (not programming or making the software backend for it), then you may be interested in
PHPmotion.