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Table 15.4Scenarios for Using Unload/Load Versus Check-Out/Check-In

Scenario Unload/Load Check-Out/Check-In
Single-user environment Yes. You don't need to track elements that have been unloaded from an application system. No.
Multiuser environment No. Yes. You need to keep track of migrated elements. Check-out elements will be locked, prevent- ing accidental updates.
Building application system from elements in other application systems Yes. It is simpler and the process is done only once, so you don't need to define a UDS. No.
Backing up of an element Yes. It is simpler. No. You don't need to define a UDS or back up the entire application system.
Require tight control over elements No. It is very flexible. Yes. Tight control can be achieved over checked out elements.
Distributed development No. Yes.
Source control required No. Yes. Elements checked out from the source application system are locked against updates.

Placing Designer/2000 Diagrams in Documents

Designer/2000 allows a variety of output methods and provides the ability to capture the output from the different diagrammers into destinations such as word processors and HTML-based tools such as Netscape and Mosaic.

Loading Diagrams into Microsoft Word 6.0This task can be achieved by using three different methods: Object Linking and Embedding (OLE), screen capture, and print file. These methods are described in greater detail in the following list.

  1. Start MS Word and open a new document.
  2. Choose Insert, Object from the menu and select Entity Relationship Diagrammer.

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To load a Word document into an ERD, complete the following steps:
  1. Start Designer/2000.
  2. From an ERD, choose Edit, Insert New Object and include a word document.

Putting Designer/2000 Repository Data on the World Wide WebPutting Designer/2000 repository data on the World Wide Web can be done by using a third-party driver such as Adobe Exchange, which supports the .PDF file format. By using this driver as the default driver, save the file in .PDF format. The file can then be downloaded on the WebServer and an HTML link established so that the file can be read through the Web, using any Web browser such as Netscape or Oracle PowerBrowser.

Reverse-Engineering Using Designer/2000

Most organizations have many existing applications that they would like to load into Designer/2000. A variety of methods are available to perform this task. The following methods are
popular:

  1. Define the database in the repository.
  2. Define primary and foreign-key constraints in the repository.
  3. Load the forms into the Oracle database and reverse-engineer them one batch at a time or one at a time.
  4. Manually insert any logic that did not get reverse-engineered.

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NOTE
Note that triggers, library attachments, procedures, and procedure calls are not reverse engineered.

Utilities, Table Entity Retrofit. This utility transforms the physical data model into a logical data model. The efficiency and usage of this method depend on how closely the physical model and the logical model match each other. The most important precaution you can take while using this utility is to make sure that primary and foreign-key constraint definitions are defined in the physical database design. It should be noted that this method does not convert a bad physical design into a good logical design. In fact, it just converts it as is; therefore, if you want to save a lot of work after the transformation is complete, you must match the physical model as closely as possible to the desired logical model. This method has the following restrictions:
Constraint definitions should exist; otherwise, all columns will become attributes instead of relationships. Shared table definitions are not retrofitted. The table should not be already mapped to an entity. If it is mapped, you must delete the association or the entity definition.

To run the retrofit utility, you can choose Utilities, Table Entity Retrofit from the RON, data diagrammer, or the entity relationship diagrammer.

Usually after the retrofitting has been performed, you will have to clean up the logical design that is generated. To do this, complete the following steps:

  1. Change the relationship names to be more meaningful, because the names generated due to retrofitting are derived from the foreign-key constraint names and are usually not very intuitive.
  2. Check the type of relationships and make sure that they are what you really want them to be; for example, mandatory foreign keys become optional/mandatory relationships, whereas optional foreign keys become optional/optional relationships.
  3. Rename the attributes to be more meaningful to the users, because in the physical design they might have been abbreviated.
  4. Do a sanity check of the resulting logical design to make sure that the entities and relationships are really what they are supposed to be, because the physical design might have implemented them differently.

Data Administration Configuration Using Designer/2000

Data administration involves the monitoring and control of a project's data. Different configurations can be used for this purpose, each having advantages and disadvantages. Designer/2000 provides features in the RON and the RAU to simplify this function.

Data administration configuration consists of knowing the application configuration that best fits your organization structure, the number of repositories that works well with this structure, and the number of users that need to be supported.

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