BMM Layer – Important things

BMM Layer – Important things

OBIEE Business Model & Mapping Layer (BMM) Layer

Out of three layer of OBIEE repository I believe the most important one is the middle layers i.e BMM layer. There very interested things which we can do in this layer.

1)  Create New Logical Columns

2) Complex Joins

3) Time Series Wizard

4) Level Based Measures

5) Aggregate Persistence Wizard 

6) Dimensional Hierarchy

7) Allows filtering the data in the logical source table

Step by step we will discuss all…

1) Create New Logical Columns

It allows to create a new logical column in BMM layer based on physical column.

2) Create Complex Joins

After creating Logical columns we can join those columns with fact tables. Thus ,we can create complex join.

3) Time Series Wizard

4) Level Based Measures

In this step we can add level based measure in dimensions. Level Based measure is a column whose values are always calculated to a specific level of aggregation.For Example , if one industry want to measure its total sales based on City, based on region or based on Country.We can set up columns to measure TotalCitySales, TotalCountrySales,TotalRegionSales.

Steps to create level based measure.

1. Create a new logical column named TotalRegionSales in the sales fact table.

2. In the TotalRegionSales properties window ,use the expression builder to create a measure based on existing sales fact table.

3. In this case, the sales column has a default aggregation rule of SUM.

4.Select level tab and associate the TotalRegionSales column with the grand total level.

5. In the business model ,the measure appears in the dimensional Hierarchy.

6. New fact column appears in the SalesFacts table.

5) Aggregate Persistence Wizard

6) Dimensional Hierarchy 

7)  Allows filtering the data in the logical source table

Using where clause in content tab in logical Table source we can filter the data in repository.