I've been reading the FSM README file lately (src/backend/storage/freespace/README), and I'm puzzled by one of the graph (the binary tree structure of an FSM file). Here it is:
4 4 2 3 4 0 2 <- This level represents heap pages
Shouldn't the last line be: 4 3 2 0
(ie, highest number of free space on the left node, lowest on the right one)
Probably just nitpicking, but still, I'm wondering if I missed something out.