DBMS Quiz Full

Duplication of data at several places is called as _______________.

• Data Inconsistency

• Database

• Data Redundancy

• Data Atomicity 

Which are important properites to identify a candidate key of Entity set

• Not Null and Unique

• Minimal of Super key and No proper subset 

• Default and Check

• Not Null and duplicate

______is an abstraction through which relationship are treated as higher level entity set.

• Specilization

• Inheritance

• Aggregation

• Generlization

Consider the employee work-team example, and assume that certain employees participate in more than one work team. A given employee may therefore appear in more than one of the team entity sets that are lower level entity sets of employee. Thus, the generalization is _____________

• Overlapping

• Disjointness

• Uniqueness

• Relational

Let E1 and E2 be two entities in an E-R diagram with simple single-valued attributes,R1 and R2 are two relationships between E1 and E2, where R1 is one-to-many and R2 is many-to-many,R1 and R2 do not have any attributes of their own,What is the minimum number of tables required to represent this situation in the relational model.

• 2

• 4

• 3

• 5

Consider 1-to-many relationship as shown in the diagram. Relationship attribute date_of_purchase will be placed in which of the following tables after converting to relational model.

• Customer entity table

• Product entity table

• Both customer and product relationship table

• One more table needs to be created

 The ___________ operation, allows us to find set of all common tuples that are belonging to both Relation R and Relation S.

• Union

• Set Intersection

• Set difference

• Join

Consider the following relations                                                                                                   

  student(id, name, address, gpa, sizeHS)                                                                                       campus(location, enrollment, rank)                                                                                                

   apply(id, location, date, major, decision)                                                                                              Identify the correct query to find name and address of all students with GPA > 3.7 and sizeHS < 1000

• Πname, address(σGPA>3.7 ∧ sizeHS<1000(student))

• σname, address(ΠGPA>3.7 ∧ sizeHS<1000(student))

• Πname, address(σGPA>3.7 ∨ sizeHS<1000(student))

• σname, address(ΠGPA>3.7 ∨ sizeHS<1000(student))

Suppose T1 table contains  3 attribues and 5 tuples and T2 table contains 3 attributes and 4 tuples, then how many attributes and tuples will be there in resultant relation if take cartesian product between T1 and  T2 (.e.(T1 X T2)

• 6 attributes and 5 tuples

• 3 attributes and 20 tuples

• 6 attributes and 20 tuples

• 6 attributes and 4 tuples

Which Relational algebra operator is not elimating duplicate tuples of resultant relation

• Union

• Project

• Select

• Intersection