That's another common variation, using a where in the outer query to select only a few of the rows from the window function.
And I've also used them as a better performing version of a full outer join - do a select of the combined fields from a window function query that is selected off of a UNION ALL. You have to jump a lot of hoops to do it, but the performance win can be worthwhile.
And I've also used them as a better performing version of a full outer join - do a select of the combined fields from a window function query that is selected off of a UNION ALL. You have to jump a lot of hoops to do it, but the performance win can be worthwhile.