Technology Questions

Encapsulation describes the ability of an object to hide its data and methods from the rest of the world 

bcoz interface does not contains any initializers and constructors to initialize its data members.

Every architecture rely on a database that is easy to maintain and gets easily configured Amazon uses the database by the name SimpleDB. This is the database that is used for cloud architecture to track the statuses of the components. The component of the system are asynchronous and discrete, it requires capturing the state of the system so that in any failure the user can easily revert back to its normal configuration. SimpleDB is schema-less database and there is no need to define the structure before the creation of any data. Every controller in the database defines their own structure and link the data to a job.

The application layer of an R/3 System is made up of the application servers and the message server. Application programs in an R/3 System are run on application servers. The application servers communicate with the presentation components, the database, and also with each other, using the message server. All the data are stored in a centralized server. This server is called database server.

The diamond problem is an ambiguity that can occur when a class multiply inherits from two classes that both descend from a common super class

Use case is nothing but the functional specification document in which all the customer requirements are documented.

Test case is a document which tells wat to test, steps to test and expected and actual results.

Icon for an Activity is defined in the manifest file.

Code

<activity android:icon="@drawable/app_icon" android:name=".MyTestActivity"></activity>

...

A foreign key is a reference to another table. It is used to establish relationships between tables. For example, relationship between employee and professor table. One employee can have multiple professors. The Primary key of employee becomes foreign key of professor.
Example:
create table employee ( id number NOT NULL, professor_id NOT NULL, Name varchar(200) Constraint prim_id Foreign key(id) references professor(professor_id) );