Questions Index

Q1. What is the data and database system? .................................................................................. 2

Q2. What is data processing? ....................................................................................................... 2
Q3. What is data specification?..................................................................................................... 2
Q4. What is a database? ............................................................................................................... 2
Q5. What are two types of views of data? ....................................................................................... 2
Q6. What are the advantages and disadvantages of the database? ................................................. 3
Q7. DATABASE USERS AND ADMINISTRATORS .............................................................................. 4
Q8. Difference Between File Processing System and DBMS ............................................................ 6
Q9. Database Architecture Of An Relational Model ........................................................................ 7
Q10. Explain the concept of Transaction Management ................................................................... 8
Q11. Explain the Components of the Storage Manager. .................................................................. 8
Q1. What is the data and database system?
Data is defined as raw facts and figures. Processing raw data to uncover its meaning produces
information. Data processing can vary from simple tasks, such as grouping data to identify trends, to
more complex activities, such as forecasting or making inferences using statistical modeling.
• Data serves as the building blocks for information.
• Information is created by processing data.
• Information reveals the meaning of data.
• Accurate, relevant, and timely data is crucial for good decision-making.

Q2. What is data processing?

Data processing involves several steps, including database management. This involves transitioning
data models into various DBMS software programs. Effective use of these programs in data
processing applications requires discipline and procedural expertise.

Q3. What is data specification?

Data specification helps define data structures. Various data structures like arrays, stacks, queues,
trees, and graphs are used for organizing data in main memory. Different mechanisms are employed
to organize data in secondary memory.

Q4. What is a database?

A database is a collection of data that describes the activities of one or more related organizations.
For instance, a university database might contain information about students, courses, and their
relationships.
Therefore, a Database Management System (DBMS) is a combination of hardware and software
used to create, maintain, and control databases, as well as manage the updating and retrieval of
stored data. It is the software that governs the creation, maintenance, and utilization of databases.

Q5. What are two types of views of data?

The data can be viewed in the following two ways:
A) Data Abstraction
B) Instances and Schemas

A) Data Abstraction
Data abstraction is a technique used to conceal some of the specifics of how data is kept and
maintained in the system.
The three levels of abstraction are:
1) Physical level.
2) Logical level
3) View level.
 I. Physical Level: This is the lowest level of data abstraction which describes "how the data is
actually stored." The definition of the stored record, the way the data fields are represented,
the internal view, and the access aids are all expressed at the physical level, or internal
schema.
II. Logical Level: This level defines "what data are actually stored in the database and what
relationships exist among those data". The conceptual schema in relational DBMS explains
each relationship that is kept in the database.
III. View Level: This is the highest level of abstraction as seen by a user. This level of abstraction
describes "only the part of the entire database which exists to simplify the interaction with
the system".
B) Instances and Schemas
As data is added and removed over time, a database changes. The term "instances of the database"
refers to the group of data that is kept there at any one time. The database schema refers to the
overall layout of the database. Schemas are rarely, if ever, updated.

Q6. What are the advantages and disadvantages of the

database?

Advantages Disadvantages
1. Reduction of Redundancies: 1. Hardware, software, and relocation costs:
Centralized data management by a Database One significant disadvantage of a DBMS is its
Administrator (DBA) prevents unnecessary data high cost. Upgraded hardware is often
duplication, significantly reducing the overall storage required to support the complex programs
space needed. and workspaces necessary for execution and
storage. In addition to the cost of acquiring or
developing the software, DBMS adds
processing overhead to ensure data security,
integrity, and sharing, which can affect
response and throughput times. Transitioning
from a traditional, separate application
 environment to an integrated one also incurs
additional expenses.

2. Elimination of Inconsistencies: 2. Problem associated with centralization:

Removing data duplication eliminates inconsistent While centralization reduces data
data files often found in redundant data. duplication, it necessitates maintaining
sufficient backups to restore data in case of a
malfunction. Centralized data availability
from a single source increases the risk of
security breaches and operational
disruptions due to failures and downtimes.
Some of these issues can be mitigated by
replacing a monolithic centralized database
with a federation of independent and
collaborative distributed databases.

3. Shared Data: 3. Complexity of Backup and Recovery: In a

A database allows multiple application programs or concurrent multi-user database system,
users to share the data it manages. backup and recovery processes are more
complicated in a DBMS environment.
Additionally, to provide access to linked data
items, a database system requires a certain
amount of controlled redundancy and
duplication, adding to the complexity of
these processes.
4. Integrity:
A centralized control system ensures that the DBMS
maintains data integrity through adequate checks.

5. Security:
Data can be highly confidential and valuable to an
organization.

6. Data Independence: Data independence is the ability

to change a schema definition at one level without
impacting schema definitions at higher levels

Q7. DATABASE USERS AND ADMINISTRATORS

A database system's primary goal is to store new data and retrieve existing data efficiently. Various
categories of people interact with the database system:
A) Database Users and User Interfaces
B) Database Administrator

A) Database Users and User Interfaces

There are four basic types of database users, distinguished by how they interact with the system:
Naive Users: These are basic users who interact with the system through predefined application
programs. They typically use forms interfaces to input data or view reports generated by the
database.
Application Programmers: Computer experts who develop application programs that interact with
the database. They use tools like Rapid Application Development (RAD) to create user interfaces,
forms, and reports with minimal coding effort.
Sophisticated Users: These users interact with the system without writing code, often formulating
requests using a database query language. Each query is processed by a query processor, which
converts Data Manipulation Language (DML) queries into instructions compatible with the storage
manager. Analysts who use OLAP (Online Analytical Processing) and data mining tools to explore
the database are examples of sophisticated users.
Specialized Users: Knowledgeable users who create specialized database applications that deviate
from the standard data processing architecture. Examples include systems used for storing data
with complex data types and environment modeling systems, such as computer-based systems,
knowledge-based systems, and expert systems.
B) Database Administrator
Having centralized control over data and the programs that access it is one of the key benefits of
utilizing a Database Management System (DBMS). An individual with such authority over the system
is referred to as a Database Administrator (DBA).
The Duties of a DBA include:
➢ Schema Definition: The DBA creates the database schema using Data Definition
➢ Language (DDL) commands. This includes defining the logical structure of database tables
(relations), such as attribute data types, lengths, integrity constraints, etc.
➢ Storage Structure and Access Method Definition: DBA determines how database tables or
indexes are stored, including using flat files, heaps, B+ Trees, and other storage structures.
➢ Schema and Physical Organization Modification: The DBA makes adjustments to the
existing physical organization and schema as needed.
➢ Granting Authorization for Data Access: DBA assigns access privileges to users based on
their roles and responsibilities. Different users may have different levels of access to data,
with administrators having the highest level of rights.
➢ Routine Maintenance:
Routine maintenance tasks performed by a DBA include:
1. Taking periodic backups of the database.
2. Ensuring there is enough disk space available at all times.
3. Monitoring database jobs and processes.
4. Ensuring that the performance is not degraded by resource-intensive tasks submitted by
users.
5. Performance tuning to optimize database performance.
Q8. Difference Between File Processing System and DBMS

Difference between File Processing System and DBMS

Sr. No. File Processing System DBMS

It coordinates with both physical and
1. It coordinates only with physical access
logical data.
Data written by one program may not be
2. Reduces amount of data duplication.
readable by another.
3. It allows predetermined access to data. Allow flexible access to data.
4. Data is not secured. Data is secured.
It allows one or more program to access
Allows multiple users to concurrently
5. different data files at the same time only
access the data files.
if files are readable.
Q9. Database Architecture Of An Relational Model
Q10. Explain the concept of Transaction Management

Transaction management in a Database Management System (DBMS) is crucial for ensuring data
integrity and consistency in multi-user environments.
The ACID properties - Atomicity, Consistency, Isolation, and Durability fundamental principles of
transaction management in a DBMS:
1. Atomicity: A transaction is atomic, meaning it either executes in its entirety or not at all.
2. Consistency: Transactions must preserve the consistency of the database.
3. Isolation: Transactions should be executed in isolation from each other; even when multiple
transactions are executing concurrently.
4. Durability: Once a transaction is committed, its effects should be permanent and survive system
failures.
Transaction management involves several components and mechanisms within the DBMS:
• Transaction Manager: Responsible for coordinating and controlling the execution of
transactions.
• Concurrency Control: Prevents conflicts between concurrent transactions that may result in
data inconsistency
• Recovery Manager: Manages the recovery process in the event of system failures or errors.
Transaction management plays a critical role in maintaining data integrity, consistency, and
reliability in a DBMS, ensuring that transactions are executed reliably and efficiently in multi-user
environments.

Q11. Explain the Components of the Storage Manager.

The storage manager of a database system acts as the interface between application programs,
queries, and the low-level data stored in the database. It converts various Data Manipulation
Language (DML) statements into low-level file system commands, thus handling the insertion,
retrieval, and updating of data within the database. Key components of the storage manager
include:
• Authorization and Integrity Manager: This component evaluates integrity requirements and
ensures the legitimacy of users' data access rights.
• Transaction Manager: It ensures the proper execution of parallel transactions and maintains
database consistency in the event of system faults.
• File Manager: This component oversees the allocation of disk storage space and manages
the data structures used to represent information stored on disk.
• Buffer Manager: Responsible for caching data in main memory and fetching it from disk
storage into memory. It plays a crucial role in enabling the database to handle data
quantities larger than the available main memory.
• Data Files: These files store the database itself.
• Indices: They provide fast access to data items, enhancing query performance.
• Data Dictionary: Stores metadata about the database structure, such as information about
tables, columns, indexes, and constraints.
These components collectively form the backbone of the storage manager, facilitating efficient
and effective management of data within the database system.
Q12. Explain Concepts of Relational Database (Including Advantages And Examples)
Key Concepts of Relational Databases
A) Tables: In a relational database, data is organized into tables. Each table, also known as a
relation, consists of rows and columns. Each row, or record, represents a single data item, while
each column, or attribute, represents a particular data field.
B) Primary Keys: A primary key is a unique identifier for each record in a table. It ensures that
each row can be uniquely identified by a specific column or combination of columns.
C) Foreign Keys: A foreign key is a column or set of columns in one table that uniquely identifies
rows in another table. Foreign keys establish a link between tables, enabling the relational
database to cross-reference data.
D) SQL (Structured Query Language): SQL is the standard language used to
interact with a relational database. It allows users to create, read, update, and delete data. SQL
provides powerful tools for querying and manipulating data, ensuring that users can efficiently
retrieve and manage their information.
E) Normalization: This process involves organizing the columns and tables of a database to
reduce data redundancy and improve data integrity. Normalization divides large tables into
smaller, more manageable pieces while establishing relationships between them.
Advantages of Relational Databases
• Data Consistency: The relational model ensures data consistency and accuracy through
rigorous data integrity constraints.
• Flexibility: SQL provides powerful querying capabilities, allowing users to retrieve and
manipulate data in various ways.
• Scalability: Relational databases can handle large volumes of data and can be scaled
horizontally and vertically.
• Security: Robust security features, including access controls and encryption, protect
sensitive data.
Some of the most widely used RDBMS include:
• MySQL: An open-source RDBMS known for its performance, reliability, and ease of use.
• PostgreSQL: An advanced open-source RDBMS with extensive features and strong
standards compliance.
• Oracle Database: A powerful commercial RDBMS with a wide range of features for large-
scale enterprise applications.
• Microsoft SQL Server: A comprehensive RDBMS developed by Microsoft, known for its
integration with other Microsoft products.