Base types are those, like int4, that are implemented below the level of the SQL language (typically in a low-level language such as C). They generally correspond to what are often known as abstract data types. PostgreSQL can only operate on such types through functions provided by the user and only understands the behavior of such types to the extent that the user describes them. Base types are further subdivided into scalar and array types. For each scalar type, a corresponding array type is automatically created that can hold variable-size arrays of that scalar type.

Composite types, or row types, are created whenever the user creates a table; it's also possible to define a "stand-alone" composite type with no associated table. A composite type is simply a list of base types with associated field names. A value of a composite type is a row or record of field values. The user can access the component fields from SQL queries.

Create a Type

To create a type :

1. Select the Database in the Tree View and select Others > Type from the toolbar
   
2. Press the New Type button
   
3. Enter Type properties and fields on the appropriate tabs of the New Type Editor
4. Click OK

Design a Type

To design a type:

1. Select the Database in the Tree View and select Others > Type from the toolbar
2. Select the type you want to design.
   
3. Press the Design Type button.
   
4. Edit Type properties and fields on the appropriate tabs of the Design Type Editor
5. Click OK
   

Delete a Type

To delete a type:

1. Select the Database in the Tree View and select Others > Type from the toolbar
2. Select the type you want to delete.
   
3. Click the Delete Type button.
4. Confirm deleting in the dialog window.