Hi Frens,

Sorry to keep you waiting  for the next post, but here it comes. Previously, in the second segment we have discussed the Presentation Server and the Presentation catalog. So, lets continue with the third segment where we will see what is the role of the BI Server in the OBIEE Architecture.

BI SERVER AND ADMIN TOOL

BI Server is a highly scalable query and analysis server.  It is the heart of the entire architecture. It efficiently integrates data from multiple relational, unstructured, OLAP application sources, both Oracle and non-Oracle.

It interacts with the Presentation server over TCP/IP  and takes the reporting request from the presentation server. Then the BI server processes the request and form logical and physical queries(in case of database as data source) and this physical query is sent to the underlying data source from which the data is processed. The BI Server interacts with the underlying database using ODBC. Hence, the entire processing of request is done by the BI server.

In the above paragraph I have mentioned that the BI server creates a logical and physical query. But how will the BI server generate this query?? How will the BI Server know what all joins need to be used?? I guess all these questions must be coming to your mind. So, lets understand the underlying process..

The BI server makes use of the BI Repository for converting the user request into logical and physical queries. The BI Repository is the metadata using which the server gets the information of the joins and the filters to be used in the query. It is the backbone of the architecture.

Now, this is the place where all the modelling is done and the role of OBIEE developers come into picture . The BI Repository is created using the Administration Tool. The repository contains three layers: Physical, BMM and Presentation Layer.

Physical Layer: Contains the tables imported from the underlying DB with appropriate joins between them.

BMM Layer: This is the Business Model layer and hence all the Business logics are implemented on this layer eg: Calculation of %age Sales, Revenue etc.

Presentation Layer: As the names specifies this layer is used for Presentation of required tables and columns to the users. The columns pulled in this layer are directly visible to the users.

Where BI Server and Admin Tool come in picture???

Now, when the users log into the BI Answers i.e the user interface, they see all the columns that are pulled on the Presentation Layer in the Repository. They choose the desired columns from there and click results button to view the report. After that the request is sent to the BI Server through the Presentation server, the BI server makes use of the BI Repository to formulate a query out of the requested report based on the joins and tables specified in the repository. This query is sent to the underlying DB and hence results are fetched.

I hope this post will clear some more concepts of yours regarding the BI Architecture. We will continue with the next segment in the upcoming post. Till then keep posting….