I'm not totally sure I follow, as you can re-reference/manipulate the subquery as much as needed. Is it for some kind of dynamic programming like finding a colu

I'm not totally sure I follow, as you can re-reference/manipulate the subquery as much as needed. Is it for some kind of dynamic programming like finding a column containing a certain value SELECT cols from table where <ANY_COLUMN> like '%foobar%'" which would need to dynamically insert values into the query select col1 from table where col1 like '%foobar%' union select col2 from table where col2 like '%foobar%' union ... This type of usage is not possible/prohibitively difficult in standard SQL but I'm interested to know if it's a different use-case.