Table of Contents
Decision Support Data Warehouses & TIME Zissis Palaskas 01 Pliroforiki
Overview
Decision Support in Organisations
The Information Needs Behind the Data Warehouse
Overview of the analyst’s tasks
OLAP vs OLTP
Overview
The DSS - Data Warehouse Landscape
Data Warehouse for Decision Support
The Data Warehouse
Subject-oriented
Integrated
Time variant
Non-volatile
Accessible
The Data Related Problems Behind the Data Warehouse
Characteristics of the integrated data warehouse
The integrated data warehouse
A generic five-tier data warehouse architecture
The Legacy & Extraction layers
The database layer
The middleware layer
The application layer
Decision Support via OLAP Systems
What is OLAP?
Some important terminology
Dimensional Analysis
Why use Multidimensional modelling
Functionality of OLAP
General structure for a Relational OLAP multidimensional model
Star-join schema in a modified RDBMS
The fact table
Identifying facts
The dimension tables
Identifying Dimensions
Drilling & Slicing
Time for Data Warehouse & Decision Support Systems
The Time Dimension
The Time Dimension
The Time Dimension
Problems in Dealing with Time
Slowly changing dimensions
The Time Dimension
Slowly changing dimensions (1)
Slowly changing dimensions (2)
The Time Dimension
Slowly changing dimensions (3)
The Time Dimension
Conforming Dimensions
Subject areas & Conforming Dimensions
Where is temporal support required?
Where to Time Support DBMS in Warehouse ?
Temporal DBMS Support in ODMG
Introduction
General concepts of a temporal database
PPT Slide
Temporal Dimensions
Measurements of time
Model of Time in TOOBIS
PPT Slide
Temporal domains
Examples without time management
Temporal dimension
Temporal dimensions
Examples with bi-temporal management
Calendar
Calendar Support - Gregorian
Absolute, relative and periodic time
Temporal conversions
Temporal User Requirements
Temporal User Requirements
Temporal User Requirements
Temporal User Requirements
Temporal User Requirements
TOOBIS & Time
OLAP Queries
OLAP Behavioural Queries
OLAP Subsetting & Classification
Temporal User Requirements
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