Component of OBIEE in detail
As it was written above the OBIEE consists of 8 interdependent components. Each of them is described in detail below
Oracle BI Server
Oracle BI Server is a high-impact query, reporting and analysis server that
provides services the other components of the Business Intelligence Suite such as
Answers, Dashboards, Data Mining, Reporting, and Analytic Applications.
The Oracle BI Server uses ODBC 2.0 //Open Database Connectivity provides a
standard software API method for using database management systems// and
JDBC //Java Database Connectivity is an API for the Java programming language
that defines how a client may access a database// interfaces to shows its services.
The services of the BI server have two primary functions. Firstly, they compile
incoming query requests into an executable code and then execute the code.
Clients of the BI Server work with a logical data display/simplified logical SQL/
independent of the data sources, and they submit them to the BI server. The
server translates the data to some combination of physical SQL and sends them
to the back-end databases.
Server administration functions include facilities such as monitoring, statistics
logging, cancellation, session and query management, and others.
The administration of the server is managed internally with using standard
protocols e.g. AD //Active Directory is an implementation of LDAP services// or
LDAP//The Lightweight Directory Access Protocol is an application protocol
for querying and modifying directory services running over TCP/IP//.
Query compilation has five phases:
- logical request generation
- code generation
The multi-functional parser accepts the full ANSI SQL92 syntax as its
input and its main function is to generate a parse tree//It is a tree data
structure that represents the syntactic structure of a string // as its
Logical Request Generation
A component of the logical request generation
takes the parse tree and makes of it a logical request tree that describes
the precise semantics of the requested data in simplified SQL.
The navigation is one of the major phases. The navigator processes
the logical request tree to an initial physical execution plan as its
output, and it uses a knowledge of content to eliminate the traditional
The rewrite is also a very important phase and its
output is also the execution plan.This phase is responsible for distributed
relational query optimization and suitable native SQL generation.
The phase of rewriting covers:
- Multi-database join plan generation
- Function shipping
- Functional compensation analysis
- Optimized SQL generation
A fed for the code generation phase is a native physical
execution plan as its input. Code generation produces
native query processing language directives to communicate with
heterogeneous or remote databases/i.e., physical SQL
generation/.It also produces a code for any remaining query processing
that has not been function shipped to remote databases.
Parallel execution directives are inserted in this code and it is used for
the Analytics execution engine.