Synonyms (PDM)

A synonym is an alternative name for various types of objects (table, view, sequence, procedure, function, synonym or database package).

Synonyms are created to:

Mask the name and owner of an object
Provide location transparency for remote objects of a distributed database
Simplify SQL statements for database users

Example

For example, table SALES_DATA is owned by user JWARD. A standard select statement on this table would be:

SELECT * FROM jward.sales_data

The database administrator can create a synonym for this table and owner and call it SALES. In this case, the SQL statement is simplified in the following way:

SELECT * FROM sales

In PowerDesigner synonyms are created for base objects. The base object is the object used to create a synonym. Base objects support multiple synonyms while each synonym must have only one base object. You can view the synonyms depending on a base object in the Dependencies tab of the base object property sheet.

If you delete the base object of a synonym, the synonym is deleted as well.

Creating a Synonym
You can create a synonym as follows:
Synonym Properties
You can modify an object's properties from its property sheet. To open a synonym property sheet, double-click its Browser entry in the Synonyms folder.
Creating a View for a Synonym
You can create views for synonyms in the same way as you create views for tables. The view query displays the content of the object used for the synonym. For example, the ORDERS_PROD_DEPT table has a synonym ORDERS:
Generating Synonyms
You can generate synonyms from the Database Generation dialog box.
Reverse Engineering Synonyms
PowerDesigner supports the reverse engineering of synonyms.

Parent topic: Building a Database Access Structure