I have a table with three columns, A, B, and Score, where A and B are some
items, and Score is some kind of affinity between A and B. There are N number
of items of each A and B, so that the total number of rows in the table are N^2.
Is there a way to fetch "top 5 items in B" for each item in A? So, for each
distinct item in A, I want to look up 5 items in B which have the highest value
in Score.
If this were to be done in DB2, I would probably use some kind of windowing
function using row_number().
