Guide to Linking SAP Business Objects (BOBJ) Universes
As a SAP Business Objects BI Developer I came to realize the huge power of linking universes (via Universe Designer). This functionality saved me a lot of time on my recent project but also gave me some painful time to figure out all the tips and tricks. Here I share some of them.
Nick Shopov is a BI Software Developer and BI Consultant with hands-on experience on improving business efficiency, transparency and profitability.
What is a SAP Business Objects (BOBJ) Universe?
BOBJ Universe is the semantic layer that separates a database from the development/business environment. In simple terms the BI Developer creates a minimal relational model of the database inside the SAP Universe Designer application and makes the database objects available to the Web Intelligence reporting.
Why Linking BOBJ Universes?
BI Developers can link two universes to each other. Linked BOBJ universes share common components such as tables, joins, classes, objects and parameters. BI Developers use this feature when they want to simulate class inheritance or duplicate a universe. On one of my projects we linked Universes to create a Master/Slave structure where the junior BI Developers did not have the required credentials to edit the master.
Nick’s Guide to Linking BOBJ Universes?
- Here is what I found out the hard way linking universes in Universe Designer:
- Master and slave universes must refer to the same database;
- Master and slave universes must be saved in the same repository;
- The master universe must be exported and imported at least once;
- Only one level of linking is possible – one master and one slave. The slave cannot become a master itself;
- If the master and the slave universes share the same table/view, the master table will be used in the slave;
- You’d better make sure that universe classes and objects do not match between the master and slave universes - collisions may occur;
- Master and slave universes must be compatible in terms of tables joining, otherwise unwanted Cartesian products may occur;
- Contexts defined in the master universe are not transferred in the slave universe.
Linking BOBJ Universe may look like a piece of cake but junior BOBJ BI Developers should keep an eye in order to ensure smooth transition to the Web Intelligence Reporting module. Happy linking... and keep an eye on the BI trends in 2014.