Vantage supports distinct and structured UDTs.
| UDT Type | Description | Example |
|---|---|---|
| Distinct | A UDT that is based on a single predefined data type, such as INTEGER or VARCHAR. | A distinct UDT named euro that is based on a DECIMAL(8,2) data type can store monetary data. |
| Structured | A UDT that is a collection of one or more fields called attributes, each of which is defined as a predefined data type or other UDT (which allows nesting). | A structured UDT named circle can consist of x-coordinate, y-coordinate, and radius attributes. |
Distinct and structured UDTs can define methods that operate on the UDT. For example, a distinct UDT named euro can define a method that converts the value to a US dollar amount. A structured UDT named circle can define a method that computes the area of the circle using the radius attribute.
Vantage also supports a form of structured UDT called dynamic UDT. Instead of using a CREATE TYPE statement to define the UDT, like you use to define a distinct or structured type, you use the NEW VARIANT_TYPE expression to construct an instance of a dynamic UDT and define the attributes of the UDT at run time.
You can only specify a dynamic UDT as the data type of (up to eight) input parameters to external UDFs. Dynamic UDTs significantly increase the number of input arguments you can pass to external UDFs.