I want to have a unique identifier(UI) made up of three fields. UI has a lot of buisiness meaning and is therefore not suitable to be the primary key.

It seems to me I am looking for a UNIQUE = "true" for the component class ?

<component class="mypackage.UI" name="UI" UNIQUE = "true">
<property column="f1" name="f1" type="string"/>
<property column="f2" name="f2" type="string"/>
<property column="f3" name="f3" type="string"/>
</component>
But there isn't such a parameter.
Am I right about the idea of using "Component" and "unique"?

In other words, I wish to create a database contraint:
CREATE UNIQUE INDEX unique ON table_that_contains_UI (f1,f2,f3)

Is it ok to create my own database contraint after schema-export ?

I will be happy to receive any responses.
/Kwan

Put unique-key="something" on all three property elements.