PostgtreSQL

Okay, so we have a table with columns A B C D in. A B C D each line in the table is unique and D is an integer. I need to find all the unique permutations of A B C with the minimum value of D. Not too hard you might think, a simple multiple group by and a MIN function. Only problem is that the table is actually 25+ columns, with 25 million rows. The simple multiple group by, now takes days to run….

I want to cry…

Anyone with any ideas please comment!!