Database Management System

____ play an important role in defining and maintaining a database for an organization.
(Fill in the blank)

Data model is collection of conceptual tools for describing
(i) data
(ii) data schema
(iii) consistency constraints
(iv) All of the above

Which statement is FALSE?

(i) Every weak entity depends on a strong entity
(ii) A weak entity can have a partial key
(iii) Every many-to-many relationship becomes a separate relation
(iv) Every relation generated from ER always has a single candidate key

Which of the following is not a feature of the relational database model?
(i) Tables with rows and columns
(ii) Use of SQL
(iii) Pre-defined data access paths
(iv) Data independence

Four DML commands are :
(i) create, update, delete, select
(ii) insert, update, drop, select
(iii) create, alter, delete, select
(iv) insert, modify, delete, select

The way a particular application views the data from the database that the application uses is a
(i) module
(ii) relational model
(iii) schema
(iv) subschema

Data models in DBMS are classified into _____ categories.
(i) 3
(ii) 4
(iii) 5
(iv) 2

The strong entity type and weak entity type participate in ____ relationship.
(Fill in the blank)

View is a :
(i) temporary table
(ii) virtual table
(iii) dynamic table
(iv) permanent table

Object-based logical models are used to describe data at
(i) logical level
(ii) view level
(iii) physical level
(iv) None of the above

A level that describes how a record is stored is:
(i) physical
(ii) logical
(iii) user
(iv) view

Key to represent relationship between tables is called
(i) primary key
(ii) secondary key
(iii) foreign key
(iv) None of the above

The different levels of data abstraction are:
(i) Physical level
(ii) Logical level
(iii) View level
(iv) all of the above

It is better to use files than a DBMS when there are
(i) stringent real-time requirements
(ii) multiple users wish to access the data
(iii) complex relationships among data
(iv) All of the above

What is an instance of a database?
(i) The logical design of the database system
(ii) The entire set of attributes of the database put together in a single relation
(iii) The state of the database system at any given point of time
(iv) The initial values inserted into the database immediately after its creation

What is a foreign key?
(i) A foreign key is a primary key of a relation which is an attribute in another relation
(ii) A foreign key is a superkey of a relation which is an attribute in more than one other relations
(iii) A foreign key is an attribute of a relation that is a primary key of another relation
(iv) A foreign key is the primary key of a relation that does not occur anywhere else in the schema

The weak entity set does not have sufficient attributes to form.
(i) Primary key
(ii) Candidate key
(iii) Both (i) and (ii)
(iv) Super key

Which of the following is not an integrity constraint?
(i) Not null
(ii) Positive
(iii) Unique
(iv) Check 'predicate'

Database is generally:
(i) system centered
(ii) user centered
(iii) company centered
(iv) data centered

The restriction placed on data is said to be:
(i) relation
(ii) attribute
(iii) parameter
(iv) constraint

An object in databases is equal to ____ + relationships.
(i) data
(ii) attribute
(iii) entity
(iv) constraint

Draw and explain the three-level architecture of the database system.

What are the five main functions of a database administrator?

Explain the three-level database architecture with a neat diagram. How does it support data abstraction and data independence?

Compare the traditional file-based systems and relational database management system approaches.

What are four main differences between file-processing system and a DBMS?

Explain integrity constraints in DBMS. Discuss different types with examples.

Construct an E-R diagram for a university registrar's office. The office maintains data about each class, including the instructor, the enrollment, and the time and place of the class meetings. For each class pair, a grade is recorded. Document all assumptions that you make about the mapping constraints.

Design an ER diagram for a Hospital Management System containing Patients, Doctors, Departments, and Appointments. Clearly identify entities, attributes, relationships, and cardinalities.

List out various constraints in relational model and explain in short.

Discuss the correspondence between E-R model construct and the relation model construct. Show how each E-R model construct can be append to the relational model using the following description of an organization:

An organization uses number of items of an equipment to produce goods. Each item is at one LOCATION, of one TYPE and has a DETAILED_DISCRIPTION. Faults on the equipment are identified by a unique FAULT_ID and are reported at a TIME_REPORTED. Any number of persons may be assigned to a fault and work on the fault until it is fixed. The TIME_FIXED is recorded as the TIME_SPENT by each person on a fault. Any number of parts may be used to repair a fault. The QTY_USED of each part is recorded against the fault. Each part is identified by a PART_ID and has a given weight and MAX_DIMENSION and can have any number of colors.

Write a short note on types of attributes and their representation in E-R model with neat figures.

With example discuss candidate key, super key, primary key and foreign key.

Explain the different integrity constraints in database system with the help of example.

Discuss the concept of generalization, specialization and aggregation.

Discuss the advantages and disadvantages of using DBMS as compared to a conventional file system.

What is weak entity set? Explain with suitable example. How weak entities are represented as relational schemas.

Write short notes on: ER models

Write short notes on: Referential integrity in database