Presentation Prepared by:

Vikram

Who are my customers and what products are they buying?

Which are ourlowest/highest margin

customers ?

What product prom--otions have the biggest

impact on revenue?

What is the most effective distribution

channel?

A single, complete and consistent store ofdata obtained from a variety of differentsources made available to end users in awhat they can understand and use in abusiness context.

A process of transforming data into information and making it available to users in a timely enough manner to make a difference

Data

Information

Subject Oriented

Integrated Data

Time-Variant Data

Nonvolatile Data

Allows for analysis of the past

Relates information to the present

Enables forecasts for the future.

Feature OLTP OLAP

Characteristics Operational processing Informational processing

Orientation Transaction Analysis

User Clerk, DBA, database professional Knowledge worker(e.g. managers)

Function Day-to Day operations Long-term informational

requirements, decision support

DB Design ER based, application-oriented Star/Snowflake, subject-oriented

Data Current; guaranteed up-to-date Historical; accuracy maintained over

time

Summarization Primitive, highly detailed Summarized, consolidated

View Detailed Summarized

Unit of Work Short, simple transaction Complex query

Access Read/write Mostly read

Focus Data in Information out

Operations Index/hash on primary key Lots of scan

DB Size 100 Mb to Gb 100 Gb to Tb

Priority High performance, High availability High flexibility, end-user autonomy

Metric Transaction throughput Query throughput

Number of Users Thousands Hundreds

16

Data Warehouse Server

(Tier 1)

Data

Warehouse

Operational

Data Bases

Semistructured

Sources Query/Reporting

Data Marts

MOLAP

ROLAP

Clients

(Tier 3)

Tools

Meta

Data

Data sources

Data

(Tier 0)

IT

Users

Business

Users

Business Users

Data Mining

Archived

data

Analysis

OLAP Servers

(Tier 2)

Extract

Transform

Load

(ETL)

www data

Data Warehousing Components

Consider, we want to create operationalsystem for order processing department of acompany.

Users can easily define the requirements as:◦ How they receive the orders◦ Check stock◦ Verify customers credit arrangements◦ Price the order◦ Determine shipping arrangements◦ Route the order to the appropriate warehouse◦ GUI they use for processing◦ How and when they use the application

Even though the users cannot fully describe whatthey want in a data warehouse, they can provideyou with very important insights into how theythink about the business.

They can tell you what measurement units areimportant for them.

Each user department can let you know how theymeasure success in that particular department.

The users can give you insights into how theycombine the various pieces of information forstrategic decision making.

Client

Warehouse

SourceSource

Query & Analysis

Integration

Metadata

Source

Client