Intro to MIS – MGS351 Databases and Data Warehouses Chapter 3.

Intro to MIS – MGS351Databases and

Data Warehouses

Chapter 3

Chapter Overview

Data Hierarchy Traditional File Environment Databases

– Relational, Hierarchical, Network

Design and Normalization Data Warehousing

Data Hierarchy

Database Table, File, Relation Records, Rows, Tuples Fields, Columns, Attributes Bytes Bits

Data Hierarchy

Figure 7-1

Traditional File Environment

Issues: Data Redundancy Data Inconsistency Data Isolation Data Integrity Security Application / Data Dependence

Traditional File Processing

Figure 7-3

Database Approach

Minimal data redundancy Data consistency Integration of data Sharing of data Uniform security, privacy and

integrity Data independence

Database Environment

Figure 7-4

DBMS Components

• Data definition language: Specifies content and structure of database and defines each data element

• Data manipulation language:Manipulates data in a database

• Data dictionary: Stores definitions of data elements, and data characteristics

Evolution of Databases

Relational Database

• Represents data as two-dimensional tables called relations

• Relates data across tables based on common data element

• Examples: DB2, Oracle, MS SQL Server

Relational Database

Figure 7-6

Hierarchical Database

• Organizes data in a tree-like structure

• Supports one-to-many parent-child relationships

• Prevalent in large legacy systems

Hierarchical Database

Figure 7-8

Network Database

Depicts data logically as many-to-many relationships

Less flexible compared to RDBMS

Lack support for ad-hoc and English language-like queries

Network Database

Figure 7-9

Database Design

Conceptual / Logical Design –

Abstract model of database from

business perspective.

Physical Design – shows how the

database is arranged on storage

devices.

ER Diagram

Figure 7-10

Knowledge about your:– Customers– Competitors– Partners– Competitive environment– Internal operations

Business Intelligence

Business Intelligence

Business Intelligence

o Online transaction processing (OLTP) - the gathering of input information, processing that information, and updating existing information to reflect the gathered and processed information. o Operational databases - databases that support

OLTP.o Online analytical processing (OLAP) - the

manipulation of information to support decision making.

Data Warehousing

Multidimensional Data Models OLAP Data Marts – subset of data

warehouse Data Mining – finding hidden

patterns and trends in data

Data Warehousing

Data warehouse - a logical collection of information gathered from many different operational databases (Extract, Transform, Load) used to create business intelligence that supports business analysis activities and decision-making tasks.

Data Warehouse

Multidimensional Data Model

Figure 7-15

Data Marts

Data mart - a subset of a data warehouse in which only a focused portion of the data warehouse information is kept.

Data Mining Tools

Distributed Databases

Figure 7-13

Databases and the Web

Figure 7-18