OBIEE 10g Architecture

Most of the people in the OBIEE community are aware of the OBIEE 10g Architecture, thought to put together a consolidated view of the architecture.
In simple way, it includes the following components;
1. Clients
1.1 Answers – Web Based
Oracle BI Answers is a set of graphical tools used to build, view, and modify Oracle BI requests. The requests are queries against an organization’s data.
1.2 Interactive Dashboard – Web Based
An Oracle BI Dashboard is used to display the results of Answers requests that are embedded in the dashboard.
1.3 Administration Tool – Windows based
The Oracle BI Administration Tool is used to build the Oracle BI repository and is the focus of this
course.
2. Oracle BI Presentation Services
Acts as middle layer in architecture in receiving and sending requests. It receives processing instructions from an Oracle BI client, retrieves the requested information from Oracle BI server, and then renders the information inside the requesting client.
3. Oracle BI Server
Is the core server behind Oracle Business Intelligence. The BI Server communicates with the BI Presentation Server via ODBC, and then connects out to the various supported data sources through ODBC, OCI, XML/A, the Essbase etc.
· Uses metadata to direct processing.
· Generates dynamic SQL to query data in the physical data sources.
· Connects natively or through ODBC to the RDBMS.
Some of the components of Oracle BI server are;
1) Intelligent Request Generator which takes the incoming queries and converts them into physical queries against the connected data source.
2) Navigator which takes the incoming query, compares it against cached requests and decides on the best results. There are some more components within the Navigator like multiple physical queries, aggregations, fragmentation etc.
3) Optimized Query Rewrite engine which handles the aggregate navigation and fragments and converts to the correct physical SQL statements.
4) Execution Engine which fires the queries to the relational, multi-dimensional, file and XML sources to fetch the data.
5) Cache Services which stores the results of previously run queries, matches incoming SQL against that used before and returns data from the cache rather than making the BI server query the underlying databases again.
6) Security Services for setting up users and groups in the RPD, filters, subject area security, links to outside LDAP servers and custom authenticators.
7) Query Governance, for placing limits on numbers of rows returned and length of query execution for users and groups.
4. Data Sources
Data sources are the physical sources where the business data is stored. They can be in any format, including transactional databases, online analytical processing databases, text files, XMLA etc. SQL is generated by Oracle BI Server against the data sources using the data source connection, information from the repository, and database-specific parameters stored in a DBFeatures.INI file.