Universe Designer provides a connection wizard that allows you to connect to your database middleware. You can create multiple connections with Designer, but only one connection can be defined for each universe. This database connection is saved with the SAP BOBJ - Universe.
Designer provides a graphical interface to select and view tables in a database. The database tables are represented as table symbols in a schema diagram. You can use this interface to manipulate tables, create joins between tables, create alias tables, create contexts, and solve loops in your schema. Web Intelligence users do not see this schema.
Building the Schema
A schema is a graphical representation of database structures. In Designer you create a schema for the part of the database that your universe represents. The schema contains :
- tables, column
- BOBJ - Derived tables (view)
Building the universe pane
Building a universe is the object creation phase of the universe development cycle. Once the schema is complete, you can build the classes and SAP BOBJ - Objects and class that users see in the Universe pane, and will use to run queries on the databases structure to generate documents and reports.
Query optimization can be based on the order of the tables in the FROM clause of the generated SQL.
Tables with many rows appear before tables with fewer rows. This order can be important especially for RDBMS that lack an optimizer feature.
It's no more the case with the actual databases because the goal of the optimizer is now based on the cost of each action (CBO) and not on the order of the table in the query (RBO).
By modifying the row count of tables, you can change their order in the FROM clause.