I've always felt sometihing was missing with Drupal Views. I never identified it while using views but I've always "felt it's presence" - or lack thereof - while building custom queries for whatever reason in MySQL. Every time I added a function like min(), max(), or sum() or tried to aggregate results with 'group by', I've said to myself silently, "I wonder if I can do this in Views.." but never checked it out until now.
I got my answer (A resounding "NO") at work when I needed to get a bunch of nodes with the same CCK referenced nid to only show ONE with the most recent publish date and the title from the parent.
The 'distinct' option in the right column doesn't work in this case because it's only applied to the nid of the focused set ("distinct nid" is clearly shown in the resulting query). And each is distinct already - different nodes with the same reference; remember?
So without the ability to choose what's distinct when using that option, building such views still leaves much to be desired.
If anyone has pointers to get this to work properly, Please let me know. Here are a few modules I tried to see if they'd help. Neither helped and neither offered the ability to override the distinct clause in the query.