Database Unit 1: Introduction to Database Concepts

Question 1

Big Data

Answer 1

High-volume, high-velocity and/or highvariety information assets that demand
cost-effective, innovative forms of
information processing that enable
enhanced insight, decision making, and
process automation.”

Question 2

Business Rule

Answer 2

A brief, precise and unambiguous
description of a policy, procedure or
principle within a specific organization.”

Question 3

Cardinality

Answer 3

“The maximum number of times an instance
in one entity can relate to instances of
another entity.”

Question 4

information

Answer 4

That data can be processed into a format.

Question 5

Data Abstraction

Question 6

Database

Answer 6

“An organized collection of structured
information, or data, typically stored
electronically in a computer system.”

Question 7

Data Dictionary

Answer 7

A centralized repository that provides
information about specific data such as
meaning, relationships to other data, origin,
usage, and format. A data dictionary stores
metadata that defines and describes data
so that it can be easily understood by
anyone who would like to use it or analyse
it at a later date.”

Question 8

Data Lake

Answer 8

“Centralized repository that allows you to
store all your structured and unstructured
data at any scale.”

Question 9

Declarative
Languages

Answer 9

“Also called nonprocedural or very high
level, are programming languages in which
(ideally) a program specifies what is to be
done rather than how to do it.”

Question 10

Entity

Answer 10

“A real-world object such as an employee or
a project.”

Question 11

Entity Integrity

Answer 11

Entity Integrity ensures that there are no
duplicate records within the table and that
the field that identifies each record within
the table is unique and never null.
“The existence of the Primary Key is the
core of the entity integrity. If you define a
primary key for each entity, they follow the
entity integrity rule.”

Question 12

Foreign Key

Answer 12

An attribute in a table that references the
primary key in another table OR it can be
null. Both foreign and primary keys must be
of the same data type.” (

Question 13

Functional
Dependency

Answer 13

“A relationship between two attributes,
typically between the PK and other non-key
attributes within a table.”

Question 14

Functional
Dependency

Answer 14

“A relationship between two attributes,
typically between the PK and other non-key
attributes within a table.”

Question 15

Index

Answer 15

“An on-disk structure associated with a
table or view that speeds retrieval of rows
from the table or view. An index contains
keys built from one or more columns in the
table or view.”

Question 16

JavaScript Object
Notation (JSON)

Answer 16

A lightweight data-interchange format. It is
easy for humans to read and write. It is easy
for machines to parse and generate.”

Question 17

Normalization

Answer 17

“The process of determining how much
redundancy exists in a table.”

Question 18

No-SQL
Databases

Answer 18

“High-performance, non-relational data
stores. They excel in their ease-of-use,
scalability, resilience, and availability
characteristics. Instead of joining tables of
normalized data, NoSQL stores
unstructured or semi-structured data, often
in key-value pairs or JSON documents.”

Question 19

Primary Key

Answer 19

“The column (field) in a relational database
that uniquely identifies the row in the table.
For example, account number is often a
primary key. A ‘composite primary key’ or
‘super key’ is made up of two or more
columns such as account number + name.”

Question 20

Referential Integrity

Answer 20

“Referential integrity requires that a foreign
key must have a matching primary key or it
must be null. This constraint is specified
between two tables (parent and child); it
maintains the correspondence between
rows in these tables. It means the reference
from a row in one table to another table
must be valid.”

Question 21

Relationship

Answer 21

“An association among entities; for
example, an employee works on many
projects. A relationship exists between the
employee and each project.”

Question 22

Transaction

Answer 22

“MySQL transaction allows you to execute
a set of MySQL operations to ensure that
the database never contains the result of
partial operations.”

Question 23

View

Answer 23

“A virtual table whose contents (columns
and rows) are defined by a query.”

Question 24

Database Management System (DBMS)

Answer 24

“A Database Management System (DBMS) is software designed to store, retrieve, define, and manage data in a database.”

Question 25

What’s the components that make up a DBMS?

Answer 25

* Hardware
The DBMS software must run on servers, and the data must be stored somewhere.
* Data.
Data can be classified as either user
data or metadata. All data has a different purposes and there are different data that can be stored in different places.
* People
Different types of people uses DBMS. The requirements would be different.
* Procedures
There are different rules that each companies manage they database.

Question 26

Waterfall Process

Answer 26

* Establishing requirement*
Statement of requirement
Analysis
System specification
Design
Design Document
Implementation
Initial System
Testing*
Released System

Question 27

hierarchical models

Answer 27

records were stored in tree structures, which means that the data was restricted to one parent entity that related to multiple child entities (one-to-many relationships).
This is an example of a few students and few course-enroll and a course can be assigned to a single student only, but a student can enroll in any number of courses and with this the relationship becomes one-to-many.

Question 28

Primary Key.

Answer 28

The column (field) in a relational database
that uniquely identifies the row in the table. For example,
account number is often a primary key. A ‘composite primary
key’ or ‘super key’ is made up of two or more columns such
as account number + name.”

Question 29

What are the three
types of relationships

Answer 29

* One-to-many relationship
A row in one table is related to many rows in another table. For example, a customer can have many orders, but each order is made by exactly one custome
* Many-to-many relationship
Many rows in one table are related to many rows in another table. For example, a customer can review many products, and the same product can be reviewed by many customers.
* One-to-one relationship
One row in a table is related to exactly one row in another table. For example, a department in the retailer has one manager, and the
manager can only manage one department at a time.

*

Question 30

No-SQL databases

Answer 30

high-performance, non relational data stores. They excel in their ease-of-use, scalability, resilience, and availability characteristics. Instead of joining tables of normalized data, NoSQL stores
unstructured or semi-structured data, often in key-value pairs or JSON documents.”

Question 31

Unstructured data

Answer 31

data that doesn’t fit neatly into tables. For example, the contents of an email message have no specific structure and that means that it can’t neatly be stored in table. Other examples include photos, files and videos.

Question 32

Semi -structured data

Answer 32

it has properties of both structured and unstructured data. Consider again the example of an email message. The content is unstructured, but the header of the email contains information like the sender and
recipients, which is structured in a known way. Looking at the
whole email including the header, it is semi-structured data.

Question 33

What are the 4 type of f NoSQL databases

Answer 33

* Document store
Data is stored in documents, typically based on JavaScript Object Notation (JSON)
* Key-value store
Data is stored as key-value pairs. Think of the way that a Dictionary in C# or a HashMap in Java stores data.
* Column store
Data is stored in rows and columns but is optimised for access in terms of the columns
* Graph store
Data is stored like in the graph data structure, with nodes, edges, and properties.

Question 34

Big data

Answer 34

high-volume, high-velocity and/or high-variety information assets that demand cost-effective, innovative forms of information processing that enable enhanced insight, decision making, and process automation.

Question 35

What are three Vs of Big Data

Answer 35

* Volume
terabytes, records,transaction and tables
* Variety
structured, unstructured, semi-structured
* Velocity
batch, real time, stream and near time