2014-12-07 15:07 GMT+01:00 Heikki Linnakangas <hlinnakan...@vmware.com>:
> On 12/07/2014 02:03 PM, Guillaume Lelarge wrote: > >> Hi, >> >> 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. >> > > No, that's not how it works. Each number at the bottom level corresponds > to a particular heap page. The first number would be heap page #0 (which > has 3 units of free space), the second heap page #1 (with 4 units of free > space) and so forth. Each node on the upper levels stores the maximum of > its two children. > > Oh OK. Thanks Heikki, that makes perfect sense. -- Guillaume. http://blog.guillaume.lelarge.info http://www.dalibo.com
