Page 170 - DCAP603_DATAWARE_HOUSING_AND_DATAMINING

Data Warehousing and Data Mining Gurwinder Kaur, Lovely Professional University

notes unit 9: Data Warehouse refreshment – ii

contents
Objectives
Introduction
9.1 Update Propagation into Materialized Views
9.2 Types of Materialized Views
9.2.1 Materialized Views with Aggregates

9.2.2 Materialized Views Containing Only Joins
9.2.3 Nested Materialized Views
9.3 Towards a Quality-oriented Refreshment Process
9.3.1 View Maintenance, Data Loading and Data Refreshment
9.3.2 The Refreshment Process is a Workflow

9.4 Implementation of the Approach
9.4.1 The Workflow of the Refreshment Process
9.4.2 Defining Refreshment Scenarios
9.5 Implementation Issues

9.6 Summary
9.7 Keywords
9.8 Self Assessment
9.9 Review Questions
9.10 Further Readings

objectives

After studying this unit, you will be able to:

l z Explain update propagation into materialized views
l z Know towards a quality-oriented refreshment process
l z Describe implementation of the approach

introduction

Your organization has decided to build a data warehouse. You have defined the business
requirements and agreed upon the scope of your application, and created a conceptual design.
Now you need to translate your requirements into a system deliverable. To do so, you create the
logical and physical design for the data warehouse.
The logical design is more conceptual and abstract than the physical design. In the logical design,
you look at the logical relationships among the objects. In the physical design, you look at the most
effective way of storing and retrieving the objects as well as handling them from a transportation
and backup/recovery perspective.

164 LoveLy professionaL university