Now I understand leow. Physical location of database is with service provider, is my understanding correct? So the owner setup the web, and does the website owner have to do database maintenance, or leave it to this task to the data center staff
That all depends upon what sort of service you sign up for. If you opt for managed hosting, the host will perform the routine tasks that are required to keep your site running smoothly. However, if your database crashes, not all hosts have the skills required restore the contents. You then need to fix it yourself or hire someone to do that for you.
Regardless of what sort of hosting plan you choose, most options include cpanel/whm where all the tools you need to maintain your site are available.