02_01_TABW90 2.0B Unit 2 BW Data Model

7/31/2019 02_01_TABW90 2.0B Unit 2 BW Data Model

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One Process is modeled at

a time.

Data storage is optimized forreporting by a Star Schema.

Characteristics are structured

together in related branchescalled Dimensions .

The key figures form theFacts.

Dimension 2

Facts

Dimension 1 Dimension 3

Dimension 4Dimension n

SAP BW Data Model


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From Data Model to Database

Star Schema

(Logical)

InfoCube(Physical)

Customer Dimension

ProductDime

nsion

ProductDimension

Quantities

RevenuesCostsTaxes

CustomerDimension

SalesDimension

CompetitionDimension

TimeDimension


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C customer-no territory chain office head office

C P T quantity sold revenue discount sales overhead stock value

T period fiscal year

P product-no product group brand category

product-no language product description

Time dimension

Product dimension

Customer dimension

Product master data: Text

Fact table

Territory 1 Territory 2 Territory 3

District 1

Territory 4

District 2

Zone 1

Territory 5 Territory 6

District 3

Zone 2

Territory 7

District 4

Territory 8 Territory 9

District 5

Zone 3

Sales hierarchy

Sales InfoCube

Customer-no Name Location Industry key

Customer master data: Attributes Sales hierarchy

Master Data and Info Cubes


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Star Schema in BW 2.0

(1) Fact Table

(2) Dimension(3) time-independent-SID

time-dependent-SIDtraditional SID Char

(4) SID Attr


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Architectural Changes: Navigational Attributes

As of BW release 2.0A there are also SID Tables fornavigational attributes.

time-dependent (/BI0/XCUSTOMER)

time-independent (/BI0/YCOSTCENTER)


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Degenerate Dimensions*

*Ralph Kimball

Customer Material Sales Person

Sales

Transaction

Degenerate dimensions arise in nearly every case where

the grain of the fact table represents an actual workingdocument like order number or invoice number.

In a degenerate dimension with order number asmember all descriptive attributes are located in otherdimensions.

Characteristics like order number group the data. Thisallows us to make analysis of materials ordered on oneorder.


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(1) Fact Table

(2) Dimension(3) time-independent-SID

time-dependent-SIDtraditional SID Char

(4) SID Attr

Degenerate Dimensions 2.0


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Where to set Line Item in InfoCube

Infocube LSSTARLI - the difference to LSSTAR


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Master Data Tables

ls star time dep yesls star time dep yes

lsnamat

lsnacus


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Master Data Tables

ls star time dep yes



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Master Data Tables - Hierarchy Tables




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An InfoCube's Star Schema

(1) Fact Table

(2) Dimensions

(3) Characteristics

month

year

day

city region country

product productgroup

sales person

division

distribution channel

sales organizationTimeDimen

sion

Product Dimension

Region Dimension

Sales

OrgDimensio

n


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Aggregates ...

... are like InfoCubes,

... summarize ("aggregate") data of the originating InfoCube,

... contain redundant information, but

... accelerate the access to that information,

... are for InfoCubes what DB indexes are for DB tables,

... are performance-enhancing features.


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Navigational attributes oftime-dependent master

data

Hierarchy levels where thestructure is time-dependent

non-BasicCubes

Aggregatescan be created on

Aggregatescannot be created on

Dimension characteristics

Navigational attributes

Hierarchy levels

Aggregates - Facts in BW


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Aggregates - Example

Country Customer Sales

USAGermanyUSAAustria

AustriaGermanyUSA

Buggy Soft Inc.Ocean NetworksFunny Duds Inc.Ocean Networks

Thor IndustriesFunny Duds Inc.Buggy Soft Inc.

1015510

102025

Fact Table: Sales Data Aggregate Tables: Sales Data

Country *Customer Space

Country Sales

403520

USA

GermanyAustria

Data for queries like sales for all countries, sales in

Germany, or overall sales can be read out of theaggregate (country *).


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Aggregates - Example using filters



AustriaGermanyUSA



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102025


Country F, GermanyCustomer *

Country Sales

15

20

Germany

Germany

Customer

Ocean Networks

Funny Duds Inc.

Data for queries like sales for all customers in Germany'can be read out of the aggregate (country F, Germany;customer *)


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Aggregates - Example using master data


USA

GermanyUSAAustriaAustriaGermanyUSA

Buggy Soft Inc.

Ocean NetworksFunny Duds Inc.Ocean NetworksThor IndustriesFunny Duds Inc.Buggy Soft Inc.

10

15510102025


Country SpaceIndustry *

Industry Sales

602510

TechnologyConsumer ProductsChemical

TechnologyConsumer ProductsTechnologyChemical

IndustryCustomer

Buggy Soft Inc.Funny Duds Inc.Ocean NetworksThor Industries

Master Data Table: Customer


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Aggregates - Example using hierarchies



AustriaGermanyUSA



1015510

102025


Country H, Level 2Customer Space

Country Sales

4055

America

Europe

All

Europe America

Germany Austria USA

Hierarchy for Country


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Aggregates - Maintenance of

Switch

on/off

Show

aggregate

hierarchy

BDS

Transpor

t

Activate &

Fill

unsavedchanges

02_01_TABW90 2.0B Unit 2 BW Data Model

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