Wow - that's interesting. I didn't know there was a btree option for
Ext3. I thought only Reiser had that. I
is btree and htree the same thing? Sorry - way out of my depth here.
I doubt they are exactly the same but the concept is that a tree
required to get speed is what they have in common. If you don't have a
tree then you have to do a linear search. If you have 100,000 files in
a directory it will take an average of 50,000 comparisons for every
file you open. That can get really slow. In a tree system you'll
probably have under 10 comparisons. That's why people prefer Reiser for
Maildir where you have lots of files in one directory.