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The Multidimensional DataModel

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The multidimensional data model is an integral part ofOn-Line Analytical Processing, or OLAP.

Why was MDDM Developed??

The Dimensional Model was Developed for

Implementing data warehouse and data marts.

MDDM provide both a mechanism to store data and away for business analysis.

Introduction to MDDM

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The two primary component of dimensional model areDimensions and Facts.

Dimensions:- Texture Attributes to analyses data.

Facts:- Numeric volume to analyse business.

COMPONENTS OF MDDM

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What is Multidimensional Data?

What is this Data, and Dimensions we are talking about???

What are all these??

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Category Weight Year onyear

growth %

Contributionto year on year

growth %points

All retailing 100 8.7All food 17.3 27.1 4.5All non-food 41.4 1.3 0.5

Department stores 7.0 25.3 1.9Textile, clothing and footwear 11.7 8.7 1.2Household goods stores 8.2 -23.5 -1.7Other stores 14.5 -6.6 -0.9

Non-store retailing 41.3 9.1 3.7

Example:

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Data is grouped or combined together in multidimensionalmatrices called Data Cubes.

In Two Dimension :-Ex: row & Column orProducts & Regions.

How is this data arranged?

DATA CUBE DIMENSIONAL MODEL

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In Three Dimension:-

Regions, products andfiscal quarters.

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slice and dice, drill down, roll up, and pivot.

Operations in Multidimensional Data Model:

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Slice is the act of picking a rectangular subset of a cube bychoosing a single value for one of its dimensions, creating

a new cube with one fewer dimension. [5]

Slice:

http://en.wikipedia.org/wiki/OLAP_cubehttp://en.wikipedia.org/wiki/OLAP_cube

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The dice operation produces a sub-cube by allowing theanalyst to pick specific values of multiple dimensions.

Dice:

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allows the user to navigate among levels of data rangingfrom the most summarized (up) to the most detailed (down).

Drill Down/Up

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allows an analyst to rotate the cube in space to see its variousfaces.

For example, cities could be arranged vertically and productshorizontally while viewing data for a particular quarter.

Pivoting could replace products with time periods to see dataacross time for a single product. [5

Pivot

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Because.OLAP implements Multidimensional Data model.

MDDM also provides faster ways of data retrieval .

The simplicity of the model is inherent because it definesobjects that represent real-world business entities.

Analysts know which business measures they are interestedin examining, which dimensions and attributes make the datameaningful, and how the dimensions of their business are

organized into levels and hierarchies.

Why is MDDM important??

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Thank you.