Is there any way in YapDatabase to get only objects with unique field values (aka SELECT DISTINCT timestamp ...)?

[Aft3rmathpwnz]

The question is the same as a subject: is there any way in YapDatabase to get only objects with unique field values (aka SELECT DISTINCT timestamp ...)? As I understand, YapDatabaseQuery has predefined "SELECT * from table_name" for every query, so how can I achieve it? Iterating over thousands of objects to get 3-4 unique values doesn't feel right