Database Unit 1: Introduction to Database Concepts Flashcards
• Explain what a database management system is. • Identify the different ways of categorising database management systems. • Identify the levels of data abstraction. • Identify the different types of databases. • Choose the appropriate type of database to use for a business problem. • Explain the concept of Big Data. (35 cards)
Big Data
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.”
Business Rule
A brief, precise and unambiguous
description of a policy, procedure or
principle within a specific organization.”
Cardinality
“The maximum number of times an instance
in one entity can relate to instances of
another entity.”
information
That data can be processed into a format.
Data Abstraction
Database
“An organized collection of structured
information, or data, typically stored
electronically in a computer system.”
Data Dictionary
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.”
Data Lake
“Centralized repository that allows you to
store all your structured and unstructured
data at any scale.”
Declarative
Languages
“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.”
Entity
“A real-world object such as an employee or
a project.”
Entity Integrity
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.”
Foreign Key
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.” (
Functional
Dependency
“A relationship between two attributes,
typically between the PK and other non-key
attributes within a table.”
Functional
Dependency
“A relationship between two attributes,
typically between the PK and other non-key
attributes within a table.”
Index
“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.”
JavaScript Object
Notation (JSON)
A lightweight data-interchange format. It is
easy for humans to read and write. It is easy
for machines to parse and generate.”
Normalization
“The process of determining how much
redundancy exists in a table.”
No-SQL
Databases
“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.”
Primary Key
“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.”
Referential Integrity
“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.”
Relationship
“An association among entities; for
example, an employee works on many
projects. A relationship exists between the
employee and each project.”
Transaction
“MySQL transaction allows you to execute
a set of MySQL operations to ensure that
the database never contains the result of
partial operations.”
View
“A virtual table whose contents (columns
and rows) are defined by a query.”
Database Management System (DBMS)
“A Database Management System (DBMS) is software designed to store, retrieve, define, and manage data in a database.”
