In this layer, you can do the following:
1. You can show fewer columns than exist in the Business Model and Mapping layer.
2. For example, you can exclude the key columns because they have no business
4. You can organize columns using a different structure from the table structure in
the Business Model and Mapping layer.
5. You can display column names that are different from the column names in the
Business Model and Mapping layer.
6. You can set permissions to grant or deny users access to individual subject areas,
tables, and columns.
7. You can export logical keys to ODBC-based query and reporting tools.
8. You can create multiple subject areas for a single business model.
9. You can create a list of aliases (synonyms) for presentation objects that can be used
in Logical SQL queries. This feature lets you change presentation column names
without breaking existing reports.
Design Tips :
- Because there is no automatic way to synchronize all changes between the
Business Model and Mapping layer and the Presentation layer, it is best to wait
until the Business Model and Mapping layer is relatively stable before adding
customizations in the Presentation layer.
- There are many ways to create subject areas, such as dragging and dropping the
entire business model, dragging and dropping incremental pieces of the model, or
automatically creating subject areas based on logical stars or snowflakes.Dragging
and dropping incrementally works well if certain parts of your business model are
- It is a best practice to rename objects in the Business Model and Mapping layer
rather than the Presentation layer, for better maintainability. Giving user-friendly
names to logical objects rather than presentation objects ensures that the names
can be reused in multiple subject areas. Also, it ensures that the names persist even
when you need to delete and re-create subject areas to incorporate changes to your
- Be aware that members in a presentation hierarchy are not visible in the
Presentation layer. Instead, you can see hierarchy members in Answers.
- You can use the Administration Tool to update Presentation layer metadata to give
the appearance of nested folders in Answers. See "Nesting Folders in Answers" for
- When setting up data access security for a large number of objects, consider setting
object permissions by role rather than setting permissions for individual columns.
- When setting permissions on presentation objects, you can change the default
permission by setting the DEFAULT_PRIVILEGES configuration setting in the