How do parameters in the Query Editor affect a Native Query?

[amorina]

Say I write a MDX or SQL query that contains date/time columns but no date/time parameters and then Import the results into Query Editor. I then use the GUI to filter rows based on a date/time column. What happens when I hit Close and Apply?

Is my entire query ran against the database/cube and THEN filtered down or does the Query Editor somehow insert the parameters into my query from the beginning? My instinct tells me the former but I am curious.