This is a known issue where the TOP query is not supported by the database itself (i.e. Vectorwise).
One way to get around this is to sort the field first (right click on it in the view and select Sort... By Field, etc). Then, create a calculated field similar to the following, place it on the filter shelf and select 'True':
Depending on how the view is set up, it may be necessary to change the way the calculation is computed (to do this right click on it and select Compute Using...)
Hope this helps!
Thanks for the workaround.