Database Reference
In-Depth Information
3. Select
Add joins by inspection …
4. Click
OK
.
3.4.2 Recursive Joins for Parent/Child Hierarchies
one area in which you always need to add joins (regardless of whether you are leveraging
a relational or flat file connection) is when creating a parent/child (or recursive) build.
to accommodate this type of build, you need to add the table/file to an existing mini-
schema (if one exists for the data source) or create a new one. once the table is in place
you simply add the join from the parent column to the child, as shown in Figure 3.11.
In this example, a flat file was used. The recursive, or self, join is the only type of join
available for a flat files within Studio. once the join is in place, the hierarchy is created
by adding both the parent and the child to the hierarchy definition.
The preceding image is different from how this would have been done in EIS. In EIS,
you would only add the child to the hierarchy. If you do this in Studio, you get very dif-
ferent results (as shown in Figure 3.12).
3.4.3 Automatic Introspection for Full Modeling and Hierarchies
The concept of mini-schema in Studio (while not overly stimulating) is important
because it represents a foundation step for ensuring you get the desired results in both
data and metadata builds. The discussion on mini-schema is incomplete without an
overview on the topic of full introspection.
Studio provides the capability of taking a relational data source and performing a
full introspection to determine both the joins and potential hierarchies. For example,
Figure 3.11
Parent/child joins.
