24 + Interview Questions in The Relational Model in Database Management Page 1 InterviewSolution

1.	A relational database consists of a collection of(a) Tables(b) Fields(c) Records(d) KeysThis question was posed to me in a job interview.Question is from Relational Database and Database Schema topic in division The Relational Model of Database Management
Answer» Right answer is (a) Tables The BEST EXPLANATION: Fields are the COLUMN of the relation or tables. Records are each ROW in a relation. KEYS are the constraints in a relation.

Discussion

2.	The most commonly used operation in relational algebra for projecting a set of tuple from a relation is(a) Join(b) Projection(c) Select(d) UnionThe question was asked in an interview for internship.My query is from Relational Query Operations and Relational Operators topic in section The Relational Model of Database Management
Answer» Correct answer is (c) SELECT To EXPLAIN: Select is USED to view the TUPLES of the relation with or without some constraints.

Discussion

3.	A ________ in a table represents a relationship among a set of values.(a) Column(b) Key(c) Row(d) EntryI have been asked this question in an online quiz.Question is taken from Relational Database and Database Schema topic in division The Relational Model of Database Management
Answer» Right CHOICE is (c) Row The best I can EXPLAIN: Column has only one set of values. Keys are constraints and row is one WHOLE set of ATTRIBUTES. Entry is just a piece of data.

Discussion

4.	The relation with the attribute which is the primary key is referenced in another relation. The relation which has the attribute as a primary key is called ______________(a) Referential relation(b) Referencing relation(c) Referenced relation(d) Referred relationThe question was posed to me in class test.Asked question is from Keys in division The Relational Model of Database Management
Answer» The CORRECT ANSWER is (C) REFERENCED relation For explanation: None.

Discussion

5.	The result which operation contains all pairs of tuples from the two relations, regardless of whether their attribute values match.(a) Join(b) Cartesian product(c) Intersection(d) Set differenceThis question was posed to me in final exam.I'd like to ask this question from Relational Query Operations and Relational Operators in chapter The Relational Model of Database Management
Answer» The CORRECT option is (b) CARTESIAN PRODUCT The best I can explain: Cartesian product is the multiplication of all the values in the attributes.

Discussion

6.	Using which language can a user request information from a database?(a) Query(b) Relational(c) Structural(d) CompilerI have been asked this question during an interview.Asked question is from Relational Query Operations and Relational Operators topic in division The Relational Model of Database Management
Answer» The correct OPTION is (a) QUERY For explanation: Query LANGUAGE is a method through which the database ENTRIES can be accessed.

Discussion

7.	The term _______ is used to refer to a row.(a) Attribute(b) Tuple(c) Field(d) InstanceI got this question during an online interview.The above asked question is from Relational Database and Database Schema in chapter The Relational Model of Database Management
Answer» RIGHT CHOICE is (B) Tuple For explanation: Tuple is one entry of the relation with SEVERAL attributes which are FIELDS.

Discussion

8.	Which one of the following attribute can be taken as a primary key?(a) Name(b) Street(c) Id(d) DepartmentI have been asked this question during an interview.I would like to ask this question from Keys in chapter The Relational Model of Database Management
Answer» Correct answer is (c) Id The BEST I can explain: The attributes NAME, street and department can REPEAT for some tuples. But the id attribute has to be UNIQUE. So it forms a primary KEY.

Discussion

9.	The term attribute refers to a ___________ of a table.(a) Record(b) Column(c) Tuple(d) KeyI had been asked this question at a job interview.Question is taken from Relational Database and Database Schema in division The Relational Model of Database Management
Answer» Correct answer is (b) Column The BEST explanation: Attribute is a SPECIFIC DOMAIN in the RELATION which has entries of all tuples.

Discussion

10.	The _______operation performs a set union of two “similarly structured” tables(a) Union(b) Join(c) Product(d) IntersectI got this question in an interview.Asked question is from Relational Query Operations and Relational Operators topic in division The Relational Model of Database Management
Answer» Correct option is (a) UNION Best EXPLANATION: Union just combines all the values of RELATIONS of same attributes.

Discussion

11.	Consider attributes ID, CITY and NAME. Which one of this can be considered as a super key?(a) NAME(b) ID(c) CITY(d) CITY, IDThis question was posed to me in an interview for internship.The doubt is from Keys topic in division The Relational Model of Database Management
Answer» The CORRECT option is (b) ID Explanation: Here the id is the only ATTRIBUTE which can be taken as a KEY. Other attributes are not uniquely identified.

Discussion

12.	Which one of the following is a set of one or more attributes taken collectively to uniquely identify a record?(a) Candidate key(b) Sub key(c) Super key(d) Foreign keyThe question was posed to me in class test.This interesting question is from Keys topic in chapter The Relational Model of Database Management
Answer» Right CHOICE is (c) Super key Best EXPLANATION: Super key is the superset of all the KEYS in a relation.

Discussion

13.	A ________ is a pictorial depiction of the schema of a database that shows the relations in the database, their attributes, and primary keys and foreign keys.(a) Schema diagram(b) Relational algebra(c) Database diagram(d) Schema flowThe question was posed to me in my homework.Origin of the question is Relational Query Operations and Relational Operators in division The Relational Model of Database Management
Answer» CORRECT CHOICE is (a) SCHEMA diagram Easiest EXPLANATION - NONE.

Discussion

14.	A domain is atomic if elements of the domain are considered to be ____________ units.(a) Different(b) Indivisbile(c) Constant(d) DivisibleI got this question in examination.Question is from Relational Database and Database Schema topic in section The Relational Model of Database Management
Answer» The CORRECT ANSWER is (B) Indivisbile Best EXPLANATION: NONE.

Discussion

15.	An attribute in a relation is a foreign key if the _______ key from one relation is used as an attribute in that relation.(a) Candidate(b) Primary(c) Super(d) SubI had been asked this question during an interview for a job.I would like to ask this question from Keys in section The Relational Model of Database Management
Answer» The correct choice is (b) PRIMARY The best I can EXPLAIN: The primary key has to be referred in the other relation to FORM a FOREIGN key in that relation.

Discussion

16.	The _______ operator takes the results of two queries and returns only rows that appear in both result sets.(a) Union(b) Intersect(c) Difference(d) ProjectionThis question was addressed to me during an interview.My enquiry is from Relational Query Operations and Relational Operators topic in division The Relational Model of Database Management
Answer» Right OPTION is (B) Intersect The BEST I can explain: The union operator GIVES the result which is the union of two QUERIES and difference is the one where query which is not a part of second query.

Discussion

17.	The_____ operation allows the combining of two relations by merging pairs of tuples, one from each relation, into a single tuple.(a) Select(b) Join(c) Union(d) IntersectionThe question was asked during a job interview.My question is from Relational Query Operations and Relational Operators topic in portion The Relational Model of Database Management
Answer» The correct ANSWER is (B) Join Explanation: Join finds the COMMON tuple in the relations and combines it.

Discussion

18.	Which one of the following cannot be taken as a primary key?(a) Id(b) Register number(c) Dept_id(d) StreetThis question was addressed to me during an interview for a job.Asked question is from Keys in section The Relational Model of Database Management
Answer» The CORRECT CHOICE is (d) STREET Explanation: Street is the only ATTRIBUTE which can OCCUR more than once.

Discussion

19.	Which one of the following is a procedural language?(a) Domain relational calculus(b) Tuple relational calculus(c) Relational algebra(d) Query languageThe question was asked in an online interview.Question is taken from Relational Query Operations and Relational Operators in division The Relational Model of Database Management
Answer» Right answer is (C) Relational algebra Best explanation: DOMAIN and Tuple relational calculus are non-procedural LANGUAGE. QUERY language is a method through which database entries can be ACCESSED.

Discussion

20.	A _____ is a property of the entire relation, rather than of the individual tuples in which each tuple is unique.(a) Rows(b) Key(c) Attribute(d) FieldsThe question was asked during an interview for a job.I'd like to ask this question from Keys in portion The Relational Model of Database Management
Answer» Correct ANSWER is (b) KEY The best I can explain: Key is the CONSTRAINT which SPECIFIES UNIQUENESS.

Discussion

21.	The ______ is the one in which the primary key of one relation is used as a normal attribute in another relation.(a) Referential relation(b) Referencing relation(c) Referenced relation(d) Referred relationI got this question during an interview for a job.I want to ask this question from Keys topic in chapter The Relational Model of Database Management
Answer» Right CHOICE is (C) Referenced relation The BEST explanation: NONE.

Discussion

22.	The subset of a super key is a candidate key under what condition?(a) No proper subset is a super key(b) All subsets are super keys(c) Subset is a super key(d) Each subset is a super keyThis question was posed to me in an internship interview.My doubt is from Keys topic in portion The Relational Model of Database Management
Answer» The CORRECT answer is (a) No PROPER subset is a SUPER key Explanation: The subset of a SET cannot be the same set. Candidate key is a set from a super key which cannot be the whole of the super set.

Discussion

23.	For each attribute of a relation, there is a set of permitted values, called the ________ of that attribute.(a) Domain(b) Relation(c) Set(d) SchemaI got this question by my school principal while I was bunking the class.Origin of the question is Relational Database and Database Schema topic in chapter The Relational Model of Database Management
Answer» The CORRECT answer is (a) DOMAIN For explanation: The VALUES of the ATTRIBUTE should be present in the domain. Domain is a SET of values permitted.

Discussion

24.	Database __________which is the logical design of the database, and the database _______ which is a snapshot of the data in the database at a given instant in time.(a) Instance, Schema(b) Relation, Schema(c) Relation, Domain(d) Schema, InstanceThe question was posed to me during an online interview.This question is from Relational Database and Database Schema in portion The Relational Model of Database Management
Answer» CORRECT answer is (d) Schema, Instance Best EXPLANATION: Instance is an instance of time and schema is a representation.

Discussion

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A relational database consists of a collection of(a) Tables(b) Fields(c) Records(d) KeysThis question was posed to me in a job interview.Question is from Relational Database and Database Schema topic in division The Relational Model of Database Management

A ________ in a table represents a relationship among a set of values.(a) Column(b) Key(c) Row(d) EntryI have been asked this question in an online quiz.Question is taken from Relational Database and Database Schema topic in division The Relational Model of Database Management

The term _______ is used to refer to a row.(a) Attribute(b) Tuple(c) Field(d) InstanceI got this question during an online interview.The above asked question is from Relational Database and Database Schema in chapter The Relational Model of Database Management

Which one of the following attribute can be taken as a primary key?(a) Name(b) Street(c) Id(d) DepartmentI have been asked this question during an interview.I would like to ask this question from Keys in chapter The Relational Model of Database Management

The term attribute refers to a ___________ of a table.(a) Record(b) Column(c) Tuple(d) KeyI had been asked this question at a job interview.Question is taken from Relational Database and Database Schema in division The Relational Model of Database Management

The _______operation performs a set union of two “similarly structured” tables(a) Union(b) Join(c) Product(d) IntersectI got this question in an interview.Asked question is from Relational Query Operations and Relational Operators topic in division The Relational Model of Database Management

Consider attributes ID, CITY and NAME. Which one of this can be considered as a super key?(a) NAME(b) ID(c) CITY(d) CITY, IDThis question was posed to me in an interview for internship.The doubt is from Keys topic in division The Relational Model of Database Management

A domain is atomic if elements of the domain are considered to be ____________ units.(a) Different(b) Indivisbile(c) Constant(d) DivisibleI got this question in examination.Question is from Relational Database and Database Schema topic in section The Relational Model of Database Management

Which one of the following cannot be taken as a primary key?(a) Id(b) Register number(c) Dept_id(d) StreetThis question was addressed to me during an interview for a job.Asked question is from Keys in section The Relational Model of Database Management

A _____ is a property of the entire relation, rather than of the individual tuples in which each tuple is unique.(a) Rows(b) Key(c) Attribute(d) FieldsThe question was asked during an interview for a job.I'd like to ask this question from Keys in portion The Relational Model of Database Management