Database Management Systems

Database Management Systems – CS403

Question No: 1   ( Marks: 1 )   – Please choose one

Which of the following is NOT a feature of Context DFD?

  • one process (which represents the entire system)
  • all sources/sinks (external entities)
  • data flows linking the process to the sources and sinks (external entities)
  • sub-processes (which explain and decomposed the major process into small processes)

Question No: 2   ( Marks: 1 )   – Please choose one

Which of the following most certainly implies the need for an entire table to implement?

► A binary relationship

► A ternary relationship   

► A recursive relationship

► An identifying relationship

Question No: 3   ( Marks: 1 )   – Please choose one

Which of the following constraints enforces entity integrity?

  • PRIMARY KEY
  • FOREIGN KEY
  • CHECK
  • NOT NULL

Question No: 4   ( Marks: 1 )   – Please choose one

Which of the following is not true about relational tables?

  • Column values are of the same kind.
  • Each row is unique.
  • Each column must have a unique name.
  • The sequence of rows is significant.

Question No: 5   ( Marks: 1 )   – Please choose one

In a conceptual model for a university, what type of relationship exists between Grade and Student entities?

  • 1:1
  • 1:M
  • M:M
  • Ternary

Question No: 6   ( Marks: 1 )   – Please choose one

Controlling redundancy in a database management system DOES NOT help to

► avoid duplication

► avoid unnecessary wastage of storage space

► avoid unauthorised access to data

► avoid inconsistency among data

Question No: 7   ( Marks: 1 )   – Please choose one

Which of the following is INCORRECT with respect to file systems?

  • At the physical level, pointer or hashed address scheme may be employed to provide a certain degree of data independence at the user level.
  • A logical record is concerned with efficient storage of information in the secondary storage devices.
  • Some physical organisations use pointers to record blocks to locate records on disk.
  • The efficiency of a file system depends on how efficiently operations such as retrieve, insert, update, delete may be performed on the information stored in the file.

Question No: 8   ( Marks: 1 )   – Please choose one

Which of the following functions are NOT performed by a database administrator?

  • Planning, designing and implementing database systems
  • Establishing standards and procedures for database systems
  • Communicating with database users
  • Allocation of storage locations and data structures

Question No: 9   ( Marks: 1 )   – Please choose one

Select the correct statement about the ANSI/SPARC architecture.

  • The conceptual level is a level of indication between the internal level and the external level.
  • The internal level in a database system will definitely be relational.
  • Any given database has many conceptual schemas and one physical schema, but it has only one external schemas.
  • The external level is not concerned with individual user perceptions, while the conceptual level is concerned with a community user perception.

Question No: 10   ( Marks: 1 )   – Please choose one

Which of the following is a correct way to implement one-to-many relationship while designing tables?

  • by splitting the data into two tables with primary key and foreign key relationships.
  • using a junction table with the keys from both the tables forming the composite primary key of the junction table.
  • by splitting each table into three
  • as a single table and rarely as two tables with primary and foreign key relationships.

Question No: 11   ( Marks: 1 )   – Please choose one

Which of the following is not a benefit of normalization?

  • Minimize insertion anomolies
  • Minimize deletion anomolies
  • Minimize updation anomolies
  • Maximize redundancy

Question No: 12   ( Marks: 1 )   – Please choose one

Consider the following relation R and its sample data. (Consider that these are the only tuples for the given relation)

EmpNo            DeptNo              ProjNo

1001                 01                      12

1001                 01                      13

1002                01                        12

1003                01                        14

Which of the following statements is NOT correct?

  • The functional dependency (EmpNo, DeptNo) -> ProjNo holds over R.
  • The functional dependency EmpNo -> DeptNo holds over R.
  • The functional dependency ProjNo -> DeptNo holds over R.
  • The functional dependency (EmpNo, ProjNo) -> DeptNo holds over R.

Question No: 13   ( Marks: 1 )   – Please choose one

The Entity Relation Model models   

  • Entities, Relationships and Processes
  • Entities and Relationships
  • Relationships
  • Entities

Question No: 14   ( Marks: 1 )   – Please choose one

As part of database naming conventions, attribute names should use suffixes such as ID, NUMBER or CODE for the _______.

  • primary key
  • foreign key
  • index
  • determinant

Question No: 15 ( Marks: 1 ) – Please choose one

User rights information is stored in

  • Physical database
  • Catalog
  • Logical database
  • Buffer 

Question No: 16   ( Marks: 1 )   – Please choose one

Making a change to the conceptual schema of a database but not affecting the existing external schemas is an example of

  • Physical data independence.
  • Concurrency control.
  • Logical data independence.
  • Functional dependency

Question No: 17   ( Marks: 1 )   – Please choose one

Which of the following is NOT a feature of Context DFD?

  • one process (which represents the entire system)
  • all sources/sinks (external entities)
  • data flows linking the process to the sources and sinks (external entities)
  • sub-processes (which explain and decomposed the major process into small processes)

Question No: 18   ( Marks: 1 )   – Please choose one

A relation (from the relational database model) consists of a set of tuples, which implies that

 ► all tuples in a relation must be distinct. 

► relational model supports multi-valued attributes whose values can be represented in sets.

► for any two tuples, the values associated with all ofheirt attributes may be the same.

► all tuples in a particular relation may have different attributes.

Question No: 19   ( Marks: 1 )   – Please choose one

Identify the constraint that limits the values that can be placed in a column.

  • NOT NULL
  • CHECK
  • FOREIGN KEY
  • UNIQUE

Question No: 20   ( Marks: 1 )   – Please choose one

Identify the correct statement with respect to normalization.

  • Normalization is a formal technique that can be used only at the starting phase of the database design.
  • Normalization can be used as a top-down standalone database design technique.
  • The process of normalization through decomposition must achieve the lossless join property at any cost whereas the dependency reservation property is sometimes sacrificed.
  • The process of normalization through decomposition must achieve the dependency reservation property at any cost whereas the lossless join property is sometimes sacrificed.

Question No: 21   ( Marks: 1 )   – Please choose one

Consider the relation Interview(CandidateNo, InterviewDate, InterviewTime, StaffNo, RoomNo) and the following functional dependencies.

FD1 : CandidateNo, InterviewDate -> InterviewTime, StaffNo, RoomNo

FD2 : RoomNo, InterviewDate, InterviewTime -> StaffNo, CandidateNo FD3 : StaffNo, InterviewDate -> RoomNo

Which of the following is correct?

  • The relation Interview is in 3NF
  • The relation Interview is in BCNF.
  • The FD3 violates 3NF.
  • The FD2 violates 2NF.

Question No: 22   ( Marks: 1 )   – Please choose one

Identify the INCORRECT statement among the given.

  • An entity may be an object with a physical existence like a car, a house or an Employee.
  • One cannot consider something which has conceptual existence like a course in a degree program as an entity.
  • Age can be considered as a single value attribute of a person.
  • An entity type describes the schema or intension for a set of entities which share the same structure.

Question No: 23   ( Marks: 1 )   – Please choose one

Structural constraints of a relationship type refer to

  • identifying the owner entity type relevant to a given entity type
  • whether the existence of an entity depends on it being related to another entity via the relationship type.
  • the role that a participating entity from the entity type plays in each relationship instance.
  • the constraints applicable in granting access to tables, columns and views in a database schema.

Question No: 24   ( Marks: 1 )   – Please choose one

A collection of concepts that can be used to describe the structure of a database

► Database
► DBMS
Data model
► Data

Question No: 25   ( Marks: 1 )   – Please choose one
An entity can be logically connected to another by defining a ____.

  • hyperlink
  • common attribute
  • primary key
  • superkey

Question No: 26   ( Marks: 1 )   – Please choose one

The ____ constraint specifies whether each entity supertype occurrence must also be a member of at least one subtype.

  • specialization
  • uniqueness
  • inheritance
  • completeness

Question No: 27   ( Marks: 1 )   – Please choose one

Database management systems, operating systems, applications and utilities are all examples of ____.

  • hardware
  • software
  • computer infrastructure
  • input and output

Question No: 28   ( Marks: 1 )   – Please choose one

Which of the following concepts is applicable with respect to 2NF?

  • Full functional dependency
  • Any kind of dependency
  • Transitive dependency
  • Non-transitive dependency

Question No: 29   ( Marks: 1 )   – Please choose one

A database system allows the following EXCEPT

  • management and control of data towards an efficient working of an organisation.
  • more critical functions in organisations to be computerised and the need to keep a large volume of data available in an up to the minute current state increased.
  • any user to access all its data.
  • integration of data across multiple applications into a single application.

Question No: 30         ( Marks: 1 )  – Please choose one

User rights information is stored in

  • Physical database
  • Catalog  
  • Logical database
  • Buffer

Question No: 31   ( Marks: 1 )   – Please choose one

The ER- data model is an example of:

  • Physical database
  • Logical database
  • Relational database
  • Conceptual database

Question No: 32   ( Marks: 1 )   – Please choose one

Which of the following is true about NOT NULL constraint?

  • enforce domain integrity
  • limit the values that can be placed in a column.
  • prevents any actions that would destroy links between tables with the corresponding data values
  • enforces the uniqueness of the values in a set of columns

Question No: 33   ( Marks: 1 )   – Please choose one

Select the correct statement among the following.

  • Role names are not technically necessary in relationship types when all the participating entity types are distinct.
  • When different entity types participate only once in a single relationship type it is called a recursive relationship.
  • Cardinality ratios for binary relationship are displayed on Entity Relationship Diagrams by using a diamond shape notation.
  • Partial participation which is also called existence dependency is displayed as a double line connecting the participating entity type to the relationship.

Question No: 34   ( Marks: 1 )   – Please choose one

Which of the following is true about relational schema?

  • The sequence of columns is significant
  • The sequence of rows is significant.
  • Contains only derived attributes.
  • Values are atomic.