Android database design

Expose the database to the other apps, there are ways:

1. By using ContentProvider and ContentResolver
2. By sharing the same user id among different apps, need to create a package context. Let the different apps belonged in the same project share the same user id is recommended, expecially on a volume datas operation. Because the different apps are treated as the same app, but actually they are not running in the save linux process.
3. By specifying the accessiblity of MODE_WORLD_READABLE and MODE_WORLD_WRITEABLE, need to create a package context.