Returning a distinct record set

[bamerza]

Is it possible to return a 'Distinct' record set?

e.g. - in SQL you can state - SELECT DISTINCT column_name,column_name FROM table_name;

How can this be replicated ?

[bamerza]

To elaborate, I know I can do it in the callback myself, but wanted to see if there was a quicker/easier way of doing it through the Persistence API.