06BR_AddingMultipleSources.pdf

Copyright 2008, Oracle. All rights reserved.

Adding Multiple Logical Table Sources

Copyright 2008, Oracle. All rights reserved.6 - 2

Objectives

After completing this lesson, you should be able to:

Describe normalized and denormalized table structures in database designs

Add multiple sources to a logical table source (LTS) for a dimension in the business model

Add a second logical table source to a dimension in the business model


Table Structures

Normalized table structure:

Consists of many tables where data has been split or normalized

Is used for inserts and updates

Does not work well for queries that perform business data analysis

Denormalized table structure:

Follows a business model and is easier to understand

Has data that may be duplicated in several locations in a database

Can take the form of a star schema

Provides better query performance


Business Challenge

Data may be spread across several physical tables and needs

to be mapped to a single logical table.

Normalized tables contain

additional product information.


Business Solution

Model multiple physical sources for the logical table:

Add multiple sources to an LTS.

Where data is not duplicated across tables

Add a new logical table source.

Where data is duplicated across tables


ABC Example: Adding Multiple Sources to a

Logical Table Source (LTS)

Add normalized tables that store product code, product type,

pricing, and supplier information to the Product dimension in

the SupplierSales business model.

Additional product information is contained in separate tables and joined to the D1_PRODUCTS root table.


Implementation Steps:

Adding Multiple Sources to an LTS

1. Import additional product tables.

2. Define keys and joins.

3. Identify physical columns for mappings.

4. Add sources to a logical table source:

Manual method

Drag method

5. Rename logical columns.

6. Add columns to the Presentation layer.


1. Import Additional Product Tables

Import additional product tables that store product code,

product type, pricing, and supplier information.


2. Define Keys and Joins

Define the keys and joins for the imported product tables.


3. Identify Physical Columns for Mappings

Locate the columns in the Physical layer with the additional

product information.


4. Adding Sources to an LTS

You can add sources to an LTS by the following methods:

Manual: Use the Properties dialog box of a logical table source to map tables and columns.

Drag: Drag columns from the Physical layer to a logical table source to automatically map tables and columns.


4a. Manual: Create New Logical Column

Create a new logical column for a logical dimension table.

1. Right-click the

logical table.

2. Create a new

logical column.

New logical column


4a. Manual: Add New Physical Source

Use the Properties dialog box of a logical table source to add a

new physical table to the source.

3. Click Add.

1. Double-click.

2.

4. Select a table.


4a. Manual: Create Column Mapping

Use the Properties dialog box of a logical table source to map a

new logical column to a physical column in the new source.

4. Use Expression Builder

to build mapping.

1. Double-click.

2.

3. Click ellipsis.


4a. Manual: End Result

D1_PRODUCTS logical table

source now maps to two physical tables: D1_PRODUCTS

and D1_PRICELIST.

Price logical column maps to thePRICE physical column in the

D1_PRICELIST physical table.


4b. Drag Method

Drag physical columns to a logical table source.


4b. Drag Method: Logical Columns Added

Dragging physical columns to a logical table source

automatically creates logical columns in the BMM layer.


4b. Drag Method: Physical Tables Added


automatically adds physical tables to the logical table source.

New tables added

Physical joins displayed

View join details.


4b. Drag Method: Column Mappings Added


automatically adds column mappings to the logical table

source.

New

mappings


5. Rename Logical Columns

Rename new logical columns with names that are meaningful

to users.


6. Add Columns to the Presentation Layer

Drag the new logical columns to the Product presentation table

to make them available to users.


ABC Example:

Adding a New Logical Table Source

Add a second logical table source to the Product dimension so

that Oracle BI Server queries only one table for Type Code and

Type information.

New logical

table source


Implementation Steps:


1. Examine the existing column mappings.

2. Identify a single table that stores both columns.

3. Add a new logical table source.

4. Define the content of the logical table source.


1. Examine Existing Column Mappings

Examine column mappings for Type and Type Code columns

in the D1_PRODUCTS logical table source.

Type maps to the

D1_PRODUCT_TYPE

table.

Type Code maps to

the D1_PRODUCTS

table.


2. Identify a Single Table That Stores

Both Columns

Examine the D1_PRODUCT_TYPE table and see that it contains

both ITEMTYPE and TYPECODE.


3. Add a New Logical Table Source

Add a new logical table source for the Products logical

dimension table that maps to the columns in D1_PRODUCT_TYPE.

New logical

table source

Column mappings


4. Define the Content of the Logical Table Source

Use the Content tab in the Logical Table Source dialog box to

define content for the source.

New logical

table source


Summary

In this lesson, you should have learned how to:

Describe normalized and denormalized table structures in database designs

Add multiple sources to a logical table source for a dimension in the business model

Add a second logical table source to a dimension in the business model


Practice 6-1 Overview:

Enhancing the Product Dimension

This practice covers the following topics:

Importing normalized tables that contain additional product information to the Physical layer of the repository

Defining physical keys and joins



Creating Multiple Sources

for a Logical Table Source (Manual)

This practice covers using the manual method to add a source

to a logical table source.



Creating Multiple Sources

for a Logical Table Source (Automated)

This practice covers using the drag method to add multiple

sources to a logical table source.




This practice covers the following topics:

Adding a second logical table source to a logical dimension table

Defining the content for a logical table source

06BR_AddingMultipleSources.pdf

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