# Technical Interview Questions and Answers :: DBMS

**Home**>

**Technical Interview Q&A**>

**DBMS**>

**Q & A**

*Accenture (161)*

*Adobe (2)*

*Alcatel-Lucent (1)*

*Broadcom Ltd (1)*

*Wipro (86)*

*Virtusa (220)*

*IBM (35)*

*Aricent (47)*

*Tech Mahindra (13)*

*TCS (171)*

*Capgemini (33)*

*iGate (162)*

*Syntel Inc. (175)*

*AT&T (1)*

*Cisco (107)*

*Sapient (72)*

*Sopra Steria (138)*

*Societe Generale (75)*

*Goldman Sachs (5)*

*TCS NQT (7)*

*Huawei (11)*

*Wipro NLTH (36)*

*Paytm (67)*

**#**C (123)

**#**C++ (187)

**#**DBMS (143)

**#**Soft. Engineering (77)

**#**Python (4)

**#**Finite Automata (6)

**#**SQL (108)

**#**Java (66)

**#**.NET (112)

**#**WebMethod (166)

**#**EDI (40)

**#**Informatica (94)

**#**Oracle Apps HRMS (106)

**#**Operating System (91)

**#**Data Structure (72)

**#**PHP (1)

**#**Unica (0)

**#**Oracle Apex (0)

**#**HR Question in TR (122)

**#**Networking (62)

**#**Hadoop (2)

**#**HTML (1)

**#**Oracle PLSQL (31)

**#**DPDK (Data Plane Development Kit) (40)

**#**Programming Qs. in TR (14)

41 / 143

**Answer:**

It is a process of analyzing the given relation schemas based on their Functional Dependencies (FDs) and primary key to achieve the properties

> Minimizing redundancy

> Minimizing insertion, deletion and update anomalies.

**Please Login First :**

42 / 143

**Answer:**

A Functional dependency is denoted by X->Y between two sets of attributes X and Y that are subsets of R specifies a constraint on the possible tuple that can form a relation state r of R. The constraint is for any two tuples t1 and t2 in r if t1[X] = t2[X] then they have t1[Y] = t2[Y]. This means the value of X component of a tuple uniquely determines the value of component Y.

**Please Login First :**

43 / 143

**Answer:**

> Every dependency in F has a single attribute for its right-hand side.

> We cannot replace any dependency X A in F-> with a dependency Y A where Y-> is a proper subset of X and still have a set of dependency that is equivalent to F.

> We cannot remove any dependency from F and still have set of dependency that is equivalent to F.

**Please Login First :**

44 / 143

**Answer:**

Multivalued dependency denoted by X -> Y specified on relation schema R, where X and Y are both subsets of R, specifies the following constraint on any relation r of R: if two tuples t1 and t2 exist in r such that t1[X] = t2[X] then t3 and t4 should also exist in r with the following properties

> t3[x] = t4[X] = t1[X] = t2[X]

> t3[Y] = t1[Y] and t4[Y] = t2[Y]

> t3[Z] = t2[Z] and t4[Z] = t1[Z]

where [Z = (R-(X U Y)) ]

**Please Login First :**

45 / 143

**Answer:**

It guarantees that the spurious tuple generation does not occur with respect to relation schemas after decomposition.

**Please Login First :**

46 / 143

**Answer:**

The domain of an attribute must include only atomic (simple, indivisible) values.

**Please Login First :**

47 / 143

**Answer:**

It is based on the concept of full functional dependency. A functional dependency X -> Y is full functional dependency if removal of any attribute A from X means that the dependency does not hold any more.

**Please Login First :**

48 / 143

**Answer:**

A relation schema R is in 2NF if it is in 1NF and every non-prime attribute A in R is fully functionally dependent on primary key.

**Please Login First :**

49 / 143

**Answer:**

A relation schema R is in 3NF if it is in 2NF and for every FD X -> A either of the following is true

> X is a Super-key of R.

> A is a prime attribute of R.

In other words, if every non prime attribute is non-transitively dependent on primary key.

**Please Login First :**

50 / 143

**Answer:**

A relation schema R is in BCNF if it is in 3NF and satisfies an additional constraint that for every FD X -> A, X must be a candidate key.

**Please Login First :**

Database Management System(DBMS) is an important subject for Freshers and Experienced candidates, Who are looking to grab a job as a **Database Developer or Administrator**. Practice the frequently Asked **DBMS Interview Questions Answers, Interview Questions on DBMS** asked at Freshers and Experienced level. Most of the listed questions here have been previously asked during the technical rounds in IT companies. You can test your SQL database knowledge by solving these questions and compare your chances of getting the job with a top IT company.

Go through the basics of Database Management System before the interview process. Here, listed DBMS interview questions are **Frequently asked during an Interview ** with different companies like Wipro, Accenture, TCS, Oracle, CTS, Adobe, TechM.

You can **Filter** the question set by the company name easily. If you are not sure about a specific answer, you can easily click and read the answer along with the explanation. So, check these **SQL Technical Interview Questions and Answers** to prepare for your dream job.