Oracle Interview Experience

Oracle Interview Questions

1) What is DBMS?

Answer: A Database Management System (DBMS) is a program that controls creation, maintenance and use of a database. DBMS can be termed as File Manager that manages data in a database rather than saving it in file systems.

2) What is a Network?

Answer: A network is a set of devices connected to each other using a physical transmission medium.

3) Explain The Main Purpose Of An Operating System?

Answer :Operating systems exist for two main purposes. One is that it is designed to make sure a computer system performs well by managing its computational activities. Another is that it provides an environment for the development and execution of programs.

4) Describe the software development process in brief:

Answer: The software development is a life cycle is composed of the following stages:

Requirement analysis

Specification

Software architecture

Implementation

Testing

Documentation

Training and support

Maintenance

5) What is wrapper class and why do we need them or where do we use it ?

Answer:-Java is an object-oriented language and can view everything as an object. A simple file can be treated as an object , an address of a system can be seen as an object , an image can be treated as an object  and a simple data type can be converted into an object (with wrapper classes). Wrapper classes are used to convert any data type into an object.

The primitive data types are not objects; they do not belong to any class; they are defined in the language itself. Sometimes, it is required to convert data types into objects in Java language. For example, upto JDK1.4, the data structures accept only objects to store. A data type is to be converted into an object and then added to a Stack or Vector etc. For this conversion, the designers introduced wrapper classes.

6) What are Wrapper classes?

Answer: As the name says, a wrapper class wraps (encloses) around a data type and gives it an object appearance. Wherever, the data type is required as an object, this object can be used.

Wrapper classes include methods to unwrap the object and give back the data type. It can be compared with a chocolate. The manufacturer wraps the chocolate with some foil or paper to prevent from pollution. The user takes the chocolate, removes and throws the wrapper and eats it.

7) What are SDLC models available?

Answer: Waterfall Model, Spiral Model, Big-bag model, Iterative Model, and V- Model are some of the famous SDLC models.

8) What is verification and validation?

Answer:

Verification:

Verification is a term that refers to the set of activities which ensure that software implements a specific function.

Validation:

It refers to the set of activities which ensure that software that has been built according to the need of clients.

9) What Is Kernel?

Answer :Kernel is the core of every operating system. It connects applications to the actual processing of data. It also manages all communications between software and hardware components to ensure usability and reliability.

10) What Is Virtual Memory?

Answer :Virtual memory is a memory management technique for letting processes execute outside of memory. This is very useful especially is an executing program cannot fit in the physical memory.

11) Who is software project manager? What is his role?

Answer: A software project manager is a person responsible for managing the software development project.

The project manager is doing the project planning, monitoring the progress, communication. He or she also manages risks and resources to deliver the project within time, cost, and quality constraints.

12) What is a Node?

Answer: Two or more computers are connected directly by an optical fiber or any other cable. A node is a point where a connection established. It is a network component that is used to send, receive and forward the electronic information.

A device connected to a network is also termed as Node. Let's consider that in a network there are 2 computers, 2 printers, and a server are connected, then we can say that there are five nodes on the network.

13) What is a query?

Answer: A DB query is a code written in order to get the information back from the database. Query can be designed in such a way that it matched with our expectation of the result set. Simply, a question to the Database.