Relational implementation of the dimensional model

You can regard this section as a prelude to covering the data warehousing Oracle Database feature, which will be discussed in detail later in this book.

Database structures behind an EUL

In the preceding section, you looked at the SQL code behind a Discoverer item. While that code represented the SELECT statement issued against a regular database table, there are some objects within Discoverer that require a set of associated objects in the underlying database to hold metadata.

Let's, for example, explore the database structures, which are implicitly defined upon creation of the HR EUL discussed in the "Post-installation tasks" section of the preceding chapter. For this, let's examine the hr/hr database schema upon which the HR EUL was created. To begin with, you can simply count the tables in the schema. To do this, connect to the database /as sysdba and then issue the following query:

SELECT count(*) FROM all_tables WHERE owner = 'HR...