DATA WAREHOUSING

OVERVIEWGOOD DECISIONS BY EFFECTIVELY MANAGING DATA

Presented to : Eng. Shahinaz Azab

Presented by : Ahmed Gamal Mohammed

SWE2 – ITInc .

Intake 30

2009/2010

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OUTLINE

Forethought What is Data Warehousing ? Architecture of Data Warehousing Data warehousing methodologies Advantages of using Data Warehousing Disadvantages of using Data Warehousing Conclusion

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FORETHOUGHT

“Today every company is an information company but not all are prepared to deal with it.“

Mark Lahr – 3M Corp

"The CEO will always get good data, but the challenge is making it available to the masses. That’s the challenge, how do you democratize decision-making?"

Eric Berg, chief administrative officer and former CIO-Goodyear.

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WHAT IS DATE WAREHOUSE ?

“collection of data that is used primarily in organizational decision making.”

-- W.H. Inmon, credited with initially using the term Data

Warehouse, 1992

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ALSO MEANS `

A data warehouse is a subject-oriented, integrated, time-variant and non-volatile collection of data in support of management's decision making process.

It is :- 1. Subject-Oriented.2. Integrated.3. Time-Variant.4. Non-volatile.

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ARCHITECTURE OF DATA WAREHOUSING

Operational database layer The source data for the data warehouse

Data access layer The interface between the operational and

informational access layer Metadata layer

The data directory - This is usually more detailed than an operational system data directory.

Informational access layer The data accessed for reporting and analyzing

and the tools for reporting and analyzing data

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TYPICAL DW ARCHITECTURE

System B

System C

System D

System A

ExtractTransformLoad

The Data Warehouse

Bu

sine

ss Mo

de

lB

usin

ess M

od

el

Self Serve

Data Sources

ETL Data Store

Data Access

Presentation

Prompted Views

Dashboards

Scorecards

Ad-Hoc Reporting

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DATA WAREHOUSING METHODOLOGIES

Bottom-up design Ralph Kimball, a well-known author on data

warehousing, is a proponent of an approach to data warehouse design

In this approach data marts are first created to provide reporting and

analytical capabilities for specific business processes.

Top-down design Bill Inmon, is one of the leading proponents of

the top-down approach to data warehouse design. In this approach

data warehouse is designed using a normalized enterprise data model. "Atomic" data, that is, data at the lowest level of detail, are stored in the data warehouse.

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ADVANTAGESOF USING DATA WAREHOUSING

1. Prior to loading data into the data warehouse, inconsistencies are identified and resolved. This greatly simplifies reporting and analysis.

2. Because they are separate from operational systems, data warehouses provide retrieval of data without slowing down operational systems.

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DISADVANTAGESOF USING DATA WAREHOUSING

1. Data warehouses are not the optimal environment for unstructured data.

2. Because data must be extracted, transformed and loaded into the warehouse, there is an element of latency in data warehouse data.

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CONCLUSION

Implementing a Data Warehouse is not a project, but a long term commitment to implement continuously improving business intelligence practices…

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Thank you for your listening

AT THE END