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| NOTE |
You cannot split or divide a resolved flow. |
Splitting a Dataflow
Splitting a dataflow creates an interim datastore between the two original elements of a dataflow. To split a dataflow, select the Split Dataflow icon. A default name is derived from the name of the dataflow. To edit the new datastore, double-click the item. You can edit it in the same manner as a datastore.
Dividing a Dataflow
If a dataflow contains multiple attributes or data elements, you might discover that the dataflow actually originates from different sources. To divide the dataflow, click Divide Dataflow. This creates an identical dataflow, with the name of the original flow followed by a number 1. Select the elements to be removed from the new dataflow (since they are identical to the original dataflow) with the down arrow. Change the name of the dataflow to a more acceptable one. Once the Dataflow Diagrammer resumes, move the new dataflow to the proper elements.
Multiple Diagrams
Using multiple diagrams in the Dataflow Diagrammer works in a similar manner as the Function Hierarchy Diagrammer and other tools in Designer/2000. When you make changes to an entity or its relationships, you can make them in either the Dataflow Diagrammer or RON. The changes will not be reflected on other diagrams that use the same entities. To consolidate multiple diagrams, choose Edit Consolidate from the menu bar. At this point, you can choose whether to consolidate a specific entity, relationship, or the entire diagram. Again, if you do not consolidate an element that has changed, you cannot edit it.
Using Colors, Fonts, and Line Width
The use of color and other variations in appearance work the same way in the Dataflow Diagrammer. In this environment you might want to make all Payroll externals be filled in with blue.
| TIP |
You might want to coordinate your use of colors in the various tools so that various functions or similar entities follow a color pattern throughout the design process. |
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Systems Design
The System Modeling tools described in the preceding sections are used to do analysis work in the life cycle of an Oracle project. The Entity Relationship Diagrammer creates a diagram of the information stored in the business model. The Functional Hierarchy Diagrammer creates a diagram of the way the information is used in the business model. Once the Entity Relationship Diagram and Functional Hierarchy Diagrams are created, the Dataflow Diagrammer creates a diagram that shows how the information flows in and out of the business functions. Now you are ready to move on to designing your system with the aid of a wizard or the Data Diagrammer, as described in the next few pages.
You perform system design at the end of analysis and the beginning of design. The tools you use bring the analysis logical model of entities and relationships into the physical model of tables and foreign keys. They bring the logical model of business functions into the physical model of reports , screens, and menus .
The icons and pull-down menus of the different tools are similar to one another and the icons and pull-down menus of the System Modeling toolset. These include new file, opening a file, saving a file, expanding and shrinking, and autolayout options.
Database Design Wizard
You use the Database Design Wizard for generating table and column definitions from entity and attribute definitions. The more effort you put into the entities and their attributes initially will save time in the physical level. Before running the tool, make sure that your entities are properly defined. To check them, you can run the Entities With No reports off the Repository Reports. The Matrix Diagrammer is also helpful in ensuring that all of the manipulation of entities ”Create, Retrieve, Update, and Delete (CRUD) ”is covered under at least one function.
Starting the Database Design Wizard
You can invoke the Database Design Wizard from either the RON or Entity Relationship Diagrammer. Select Utilities Database Design Wizard.
Initially, the tool loads all the entity and table information available in your application.
The Table Mappings Tab
The first screen that appears is the Table Mappings tab. (See Figure 32.6.) It contains all the entity names . If the entity is currently mapped to a table, the table name will show. You now have the option of re-creating the entire table, updating specific attributes in the table, or leaving the mapping as it exists. If you want to generate or regenerate an entire entity into a table, select the In Set box.
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If your logical model included supertypes and subtypes, the physical level must resolve these issues. You will need to decide if the table will become joined or left separately. The Table Mappings tab offers the capability of resolving these issues at the time of the conversion from the logical to physical model. If the entity is mapped, the subtype is a different table from its supertype. Include is utilized only for entity subtypes. The usage of this option creates a table of the combined subtype and supertypes with a Discriminator column. Arc signifies that the subtype will be separate from the supertype and the common attributes among the subtypes will be stored in the supertype table.
Figure 32.6.
TheTable Mappings
tab.
If the Design Wizard has not yet generated a table name, leave the table name blank. It is generated when the table definition is generated.
The Column Mappings Tab
On the Column Mappings tab (see Figure 32.7), you can choose columns to generate initially or columns to regenerate. You might want to regenerate a table because it relates to a new entity or because you did more analysis and added new attributes to the entity. On the Column Mappings tab, you can remap attributes to existing columns, add new attributes, or add new columns. Attributes are already included if an entity is in the set, so you probably won't need to add them. You can select a single attribute without selecting the table. If the table does not exist, only these attributes selected generate columns in the table.
The Primary Keys Tab
On the Primary Keys tab, you can choose primary keys to generate initially or primary keys to regenerate. Existing primary and unique keys are automatically included here. On the Primary Keys tab, you can remap attributes to existing unique keys or add new unique keys to the table. If an entity is in the set, there is no reason to add the keys; they are included. You can select a single key without selecting the table. If the table does not exist, only these unique IDs selected will generate unique keys in the table.
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