What's the difference between a group-to-group and a column-to-column link?
I normally use a column-to-column link to join queries in my data model. One time, however, I got :
Cannot implement column link for this detail SQL query. Converting to group link.
The child query is a 'SELECT columns FROM (SELECT columns .... ) WHERE rownum < 4', which could be why it's forcing me. I know I could remove the outer query and filter just the first three rows, but I'm intrigued as to what the differences are. Thanks in advance.
Paul Williams