dbms_batch2_28_jan_2020_quiz

Which command is used to remove all rows from a table?

• Delete

• remove

• truncate

• both A and B

A super key is a set of one or more attributes that, taken collectively, allow us

• to make the key most powerful for faster retrieval

• to increase effectiveness of database access

• to identify uniquely an entity in the entity set

• none of the above

The number of entities to which another entity can be associated via a relationship set is expressed as

• entity

• schema

• attributes

• cardinality

In an E-R diagram double lines indicate

• Cardinality N

• Multiple participation

• Total participation

• both A and B

What is data integrity?

• It is the data contained in database that is non redundant

• It is the data contained in database that is accurate and consistent

• t is the data contained in database that is secured

• It is the data contained in database that is shared

• none of the above

The keyword to eliminate duplicate rows from the query result in SQL is

• DISTINCT

• NO DUPLICATE

• UNIQUE

• None of the above

The ……………….. refers to the way data is organized in and accessible from DBMS.

• database hierarchy

• data organization

• data sharing

• data model

What operator tests column for the absence of data?

• IS NULL operator

• ASSIGNMENT operator

• LIKE operator

• NOT Operator

The subset of super key is a candidate key under what condition ?

• No proper subset is a super key

• All subsets are super keys

• Subset is a super key

• Each subset is a super key

A _____ is a property of the entire relation, rather than of the individual tuples in which each tuple is unique.

• Rows

• Key

• Attribute

• Fields