4.3 Database Management Systems

Question 1

Database

Answer 1

An organized collection of electronically stored data

DBMS is the software that helps manage the database: it stores, modifies and retrieves data

Question 2

Hierarchical Database

Answer 2

The “original” database:
relationships were developed in terms of parent-child tree structure

• Redundant, too much time&effort to implement and maintain

Question 3

Relational Database

Answer 3

Data is stored in tables that are linked together & association tables (where links are recorded in separate tables)

Columns: fields/attributes - the concept being described
Rows: instances of the concept being described

Primary Key: unique identity

Foreign Key: matching value with primary key

Question 4

Advantages of Relational Databases

Answer 4

1. Data is stored once (all linked tables show the changes)
2. Complex queries can be created
   Creating, inserting, updating, deleting is done in Structured Query Language SQL
3. Improved Security
4. Flexible, scalable, extensible

ERP, SCM, CRM all use relational databases for data processing, storage, retrieval

Question 5

Data Warehouse

Answer 5

Purpose: integrate & organize data from different sources, used for reporting and analysis

Support data structures = star schema

Question 6

Star Schema

Answer 6

Easy to understand
The centre is the focus of the analysis
Can be processed efficiently

1. Fact Tables: business transactions; simple structure; quantitative
2. Dimension Tables: provide context by giving meaning to the facts

Question 7

noSQL Database

Answer 7

Does not organize data by tables and does not use SQL query language
They use: stores, graphs, document data

The ability to efficiently process large amounts of data and unstructured data

Question 8

Self-Service Business Intelligence (SSBI)

Answer 8

(Deals with big data)
1. Extended capabilities for extracting, profiling, cleaning and analyzing data; integration & improving veracity

2. Easy to use

PowerBI