Physical Layer in OBIEE

Physical Layer:The name itself is saying,it is having the direct relation between the repository and database.This is the one o f the most important layer in the repository.The query will be executed from the physical layer only.Joins in the other layers should be same with the physical layer.We can't rename the object names in the physical layer.In this layer we can import the data,creating connection pools,alias tables,duplicate tables,opaque views, keys and joins.

Data sources:We can Import the data from different Data sources like oracle, my-sql, excel sheets, XML data and cubes(OLAP and ESS base) by using different drivers. Data will be imported with key or without keys.

Connection pool:We can create a multiple connection pools for single repository to increase the performance.These are used for accessing users,variables and implementing the security etc.

Tables:Alias and duplicate tables will be created in the physical layer.

Alias table:It is copy of parent table and always functionally depending on the parent table.Alias table will be created for re-use the same table for different purpose.

Duplicate table:It is a copy of parent table but don't have the  relation,once created.

Keys:If u import the tables without keys,here we can create the keys based on the data-modelling.The joins will be established in the physical layer only based on the primary and foreign key relation.

Opaque views:Opaque view is physical select statement,which does not occupy any space in the repository.We can deploy or un-deploy from repository to database.