Friday, June 3, 2011

OBIEE RPD Security Matrix

I have just come across a scenario when I was introducing a new RPD Group and understood how the least restrictive criteria works on groups and would like to share the knowledge. Please find attached excel work sheet which gives info on security derivation when same level group involved for a user\group. I would like to have your valuable comments\input if you have any :)






Case#\Filter Global Group Continent-1 Group Continent-2 Group Filter Comments
TC #01 C1 C1
TC #02 C1 C2 C2
TC #03 C2 C3 C4 (C3) or (C4) Least Restrictive
TC #04 C2 C3 and C2 C4 or C1 (C3 and C2) or (C4 or C1) Least Restrictive
TC #05 C3 C4 or C1 C4 or C1 Least Restrictive

Wednesday, June 1, 2011

OBIEE Performance

Physical Layer
1. Enable DB features
2. Push the calculation to DB
3. Set up the no of connection in efficient manner based on the Oracle recomended way.
4. Physical Table "Select" Type i.e Opaque views can be avoided and introduce Materalised Table provided if ROLAP is oracle.

BMM layer
1. Set the aggregation Level proper level in each LTS of the Logical Table.
2. Set the estimation level for each level in Dimension. To calculate the estimation level, right click and run the Estimation level or Specify the ration between the levels.

Presentaion layer.
1. Rule of seven, each of the presentation table shows only seven columns (oracle recomendation) if it is possible.
2. Limit theno of the facts on each SA avoid user to link the fact which is not intended to link.

Thursday, May 26, 2011

What is degenerated Dimension?


The fact table in below contains two additional attributes, order_id and order_line_id, which are neither facts nor foreign keys. These columns reference a specific order and the line number within an order respectively. They are dimensional attributes that have been placed in the fact table rather than a dimension table. Although they could have been placed in the order_type table, doing so would have dramatically increased the number of rows in the table. When a dimensional attribute is located in the fact table, it is known as a  degenerate dimension. - By Christopher Adamson




Wednesday, May 25, 2011

Multiple Datasource

I have two data source in physical layer one is Oracle another one is Essbase, In BMM layer Fact referring both data source tables,
My Question : Is it affect performance?.

I assume the grain is same, so no performance problem

Thursday, May 19, 2011

OBIEE Discussions

When does new LTS (Logical Table Source ) gets created?

1. If aggregate tables available for same Logical Fact, create a new LTS and set the level appropriately.
2. If fact tables contains various level of data, each level can be filtered and create as new LTS.
3. If a dimension is snow flaked, then if report requires one of the snowflake. Then create a new LTS.

Good link for Column Hiding
http://nerdsofobiee.wordpress.com/tag/column-level-security/