Re: Hashing and directories

[Alexander Viro]

On Sat, 1 Jan 2000, Pavel Machek wrote:

> Hi!
> 
> >  I was hoping to point out that in real life, most systems that
> > need to access large numbers of files are already designed to do
> > some kind of hashing, or at least to divide-and-conquer by using
> > multi-level directory structures.
> 
> Yes -- because their workaround kernel slowness.

Pavel, I'm afraid that you are missing the point. Several, actually:
	* limits of _human_ capability to deal with large unstructured
sets of objects
	* userland issues (what, you thought that limits on the
command size will go away?)
	* portability

The point being: applications and users _do_ know better what structure
is there. Kernel can try to second-guess them and be real good at that, but
inability to second-guess is the last of the reasons why aforementioned
strategies are used.