Android utilizes the SQlite database by default. However, for security reasons, the sqlite3 is not installed on many Android devices (At least on Android 2.3.3). To work with it, one could root the phone and install sqlite3 by hand. The another way to do it is working with the emulator.
Because the emulator is a completely open device, there is not restriction to access to the database or to the shared preferences. Once the emulator has been started, the DDMS of eclipse could be used to extract the database and check its structure and the contents.
To make the thing even easier, there is a plugin for the eclipse which allow the coders to access the data inside of DDMS:
Official web page: