To create a new procedure (later on you can switch it to a stored function), click on the
Stored Procedure () icon on the
Palette toolbar. Your mouse cursor will change its appearance. Click on
the diagram area to create a new stored procedure. A rectangle with the name of the stored procedure
will appear in the diagram:
Visual representation may vary: if an object has at least one output parameter, then
it will be shown as above (procedure notation). If return type is trigger, then it will be shown in trigger
procedure notation. If return type is language_handler, then it will be shown in Language Handler
procedure notation. In other cases it will have function notation represantation.
Basically, PostgreSQL has only functions.
To edit parameters of the stored procedures and functions use
Stored Routine Editor.