Database Reference
In-Depth Information
Figure 3.6
User-defined table definition.
It is important to note that queries through user-defined tables are extremely slow
and should be used primarily as temporary objects while a proper view is being cre-
ated within the relational source. They are most useful in validating the SQL that
will ultimately be used in a proper view, prior to making the formal request from the
database team.
3.3.4.1 Creating a User-Defined Table
1. right-click on the desired data source.
2. Select
New->User-Deined Table …
3. In Figure 3.6's dialog box, enter a table name and type/paste the table defini-
tion SQL.
4. Click
OK.
a.
If the SQL validates without error, the table is created.
b.
If there is an error, it displays in the uI (user interface).
3.4 moDeling the Data sourCe
After creating the initial connections, the next step prior to actually creating hierar-
chies is to determine whether or not modeling need be applied to the tables or files.
modeling, quite simply, is the creation of joins and the creation of mini-schema for the
data source. Studio
does not
require that you create a mini-schema to build dimension-
ality (Figure 3.7).
The only times you must have a mini-schema in place are when you are doing the
following:
1. Creating hierarchies across multiple tables (only available for relational sources)
2. Loading relational data from within Studio
3. Creating a hierarchy from a single table/file using parent and child columns
Just a brief word about item 2. It may sound strange to think of loading of data with-
out using Studio. It is often assumed that because you are using Studio to model a data
source and build a prototype you would also leverage Studio to load data. We will touch
