Beginner needs help!

this is soorya studying btech. i am doing some mini projects for my uml lab. i am getting a lot of doubts where to start . actually we will follow a noun phrase approach. but after identifying use cases and actors the problem begins.can we include database as an actor or it should be represented as a component in component diagram. if so what does the database has to do with the use cases .tell me any use case the database initiates.,1410,31863,00.html

hope they will be useful