Database/DBMS Interview Questions And Answers

Database/DBMS Interview Questions And Answers - Part IX.

41) Define The Types Of Data Integrity Rules?

Answer: Data Integrity falls under the following three categories:

a) Entity Integrity: Entity integrity ensures that each row can be uniquely identified by an attribute
called the Primary key. The Primary key cannot have a NULL value.
b) Domain Integrity:Domain integrity refers to the range of valid entries for a given column. It ensures that there are only valid entries in the column.
c) Referential Integrity: Referential integrity ensures that for every value of a Foreign key, there is a
matching value of the Primary key. It states that "Foreign Key can be either a NULL value or should be Primary Key value of other relation".

42) What Is A Table? What Is A Tuple? What Is A Relation?

Answer: Table is a representation of a relation having records as rows and attributes as columns.

Tuple is nothing but a row in a table.

A relation consists of a homogeneous set of tuples. Informally a relation is a table.

Relations can be represented as two-dimensional data tables with rows and columns. The rows of a relation are called tuples. The columns of a relation are called attributes.
The attributes draw values from a domain (a legal pool of values). The number of tuples in a relation is called its cardinality while the number of attributes in a relation is called its degree.

A relation also consists of a schema and an instance. Schema defines the structure of a relation which consists of a fixed set of attribute domain pairs. An instance of a relation is a time-varying set of tuples where each tuple consists of attribute-value pairs.

43) What Are Extension & Intension?

Answer: Extension is the number of tuples (rows) present in a table at any instance. This is time dependent where as Intension is a constant value that gives the name, structure of table and the constraints laid on it.

A database is divided into schema and data. The schema describes the intentions (types) and the data describes the extension (data).

44) What Is A View? How It Is Related To Data Independence?

Answer: A view may be thought of as a virtual table, that is, a table that does not really exist in its own right but is instead derived from one or more underlying base table. In other words, there is no stored file that direct represents the view instead a definition of view is stored in data dictionary.

Growth and restructuring of base tables is not reflected in views. Thus the view can insulate users from the effects of restructuring and growth in the database. Hence accounts for logical data independence.

45) What Is A View? Discuss The Difference Between A View & A Base Relation?

Answer: View is the dynamic result of one or more relational operations operating on the base relations to produce another relation.

Base relation exists as a set of data in the database. A view does not contain any data, rather a view is defined as a query on one or more base relations and a query on the view is translated into a query on the associated base relations.

ALSO CHECK THE BELOW FAQ's:

46) What Is A Key? What Are Different Types Of Keys In A Database?
47) What Is A Primary Key & Secondary Key?
48) What Is A Candidate Key & Alternate Key?
49) What Is A Super Key & Composite Key?
50) What Is Foreign Key?

51) What Is Normalization. Explain It In Detail?
52) What Is The Need For Normalization In DBMS?
53) What Are The Goals Of Normalization In DBMS?
54) State The Benefits Of Normalization In DBMS?
55) What Is Functional Dependency?

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Tell Me Something About Yourself - Interview Answers.

Try to introduce some of your most important employment-oriented skills as well as your education and accomplishments to the interviewer. Answer to this question is very important because it positions you for the rest of the interview . That's why this statement is often called the "Positioning Statement". One should take the opportunity to show his/her communication skills by speaking clearly and concisely in an organized manner. Since there is no right or wrong answer for this question hence it is important to appear friendly. YOUR ANSWERS CAN BE: 1) I am a person with strong interpersonal skills and have the ability to get along well with people . I enjoy challenges and looking for creative solutions to problems. 2) Besides the details given in my resume, I believe in character values, vision and action. I am quick in learning from mistakes. I am confident that the various tests that you have conducted will corroborate my competencies apti

HR Interview Questions With Simple Answers - Top 30.

Here are some very important HR questions which are often asked during Interviews and I believe these answers can really help you to get through....... Click on them to view the answer: 1) Tell Me Something About Yourself ? 2) What Are Your Strengths? 3) What Are Your Weaknesses? 4) How Do You Handle Pressure / Can You Work Well Under Pressure? 5) What Are Your Short Term Goals? 6) What Are Your Long Term Goals? 7) Where Do You See After 5 Years? 8) Why Should We Hire You? 9) What Is Your Salary Expectation? 10) Why Do You Want To Leave Your Current Job? 11) Do You Prefer To Work Alone Or As A Team Player? 12) What Made You Choose Your Major / Stream? 13) Why Didn’t You Pursue A Career In Your Major / Stream? 14) Why Do You Want To Work For Us? 15) Are You Willing To Travel? 16) Are You Willing To Take Risks? 17) What Do You Know About This Company? 18) What Do You Seek From A Job? 19) How Do You Evaluate Success? 20) During Your Performance Rev

Sample Cover Letter / Job Application.

To The General Manager (HR) [ Name and Designation (Bold Words)] Infosys Limited Delhi – 110001 Uttam Agrawal Gandhi Chowk, Bhartee Street [ Name Bhawanipatna, Kalahandi Contact Address Orissa – 766001 Telephone No.] Ph. no - +91-9438170446 [Sub: Application for the position of ___________ in your esteemed organization.] Respected Sir, (Always use ‘Respected’) With reference to your advertisement dated 14th may’ 08 in The Times of India for the position of ___________ . I would like to place myself as a strong contender before you. OR This has reference to your advertisement dated 14th may’ 08 in The Times of India for the position of ____________. In the said connection I take this opportunity to apply for the said position as a strong contender. /*This is the Introduction i.e the first paragraph of your application/* ( Now the Second Paragraph is the Self Introduction) Try to start the second paragraph with the below mentioned lines: - I have the p

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