CODEWITHSUNDEEP
repositoryobiee
omer
omer

Reputation: 1

Oracle BI repository

I am new to Oracle BI. I have been reading documents, tutorials, oracle by example guides and watching some videos. But I cannot answer some questions which are confusing my mind.

1-) Why we have 3 repository layer? In the tutorials, they are dragging objects from physical layer to business model and mapping layer. In this layer they are renaming table names. Then they are dragging objects from Business Model to Presentation Layer. In this layer they are renaming table names again and they are deleting some columns. I think that we can use just physical layer and presentation layer. In presentation layer we can rename table names and remove some columns.

2-) In physical layer, we are importing objects from data sources. We can import tables, views and foreign keys. What is the best practice for designing business model? I created a test repository. I imported tables, views and foreign keys from database. But when I try to check consistency ( afte preparing presentation layer), I took error messages about self joins in the physical layer. Can I solve self join problem?

3-) Should I import only tables and views from database in physical layer? I think that if I do not ceate joins manually after import operations, Oracle BI Server may not prepare correct sql statements. We have a big database (maybe 500 tables), so if I dont import foreign keys, manually creating foreign keys will be a massive manual process. I also do not know which foreign keys are mandatory for a well designed business model?

4-) When database tables changed( for. ex. added new column), are these changes automatically updated to the physical layer?

Thank you..

Upvotes: 0

Views: 2995

Answers (1)

gerardnico
gerardnico

Reputation: 1073

1- Physical Layer = Physical Data Model (Database Implementation) Business Model and Mapping Layer (BMM) = Logical Data Model (Declarative way to say which table is a fact, dimension, ...) Presentation Layer + What the end-user, client see

The most important to see is that the definition of the BMM is the most important as it permits the generation of the physical query (query against the database).

More check this link: http://gerardnico.com/wiki/dat/obiee/logical_business_model#centralized_and_consistent_conceptual_data_model

2- To correct the self-join, you have to create an alias of your table in the physical layer http://gerardnico.com/wiki/dat/obiee/alias#physical_table_alias

3- You can import all. also foreign key ;-) the best practice is to import only what you need.

4- No but you have an utility to do the job. You can find it in the utility box.

And the best OBIEE forum is here: forums.oracle.com/forums/forum.jspa?forumID=378

Success

Nico

Upvotes: 2

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