I\'m developing a little project plan and I came to a point when I need to decide what local databse system to use.
The input data is going to be stored on webserver
Pick anything that's available, but code against interfaces only, that way you can easily switch between them.
For production, I'd say either MS SQL for large projects, (or express for mid level) simply because of the close integration with VS and Sqlite for smaller projects.
Given the description, I would think that Sqlite would be a good choice, since it's the simplest/lowest overhead.