Re: Future Ideas wiki page

[David Lang <david.lang@xxxxxxxxxxxxxxxxxx>]

On Wed, 13 Jan 2010, Wil Cooley wrote:

> And anyway, would it
> be faster to open and list 1,000 files in 23 directories than to open one
> directory and list 23,000 files? Would that be overshadowed by the cost of
> opening all 23,000 files (which I presume it would need to if it were resorting
> to listing them).

there are two scenerios that are important here

1. open a directory and list 23,000 files

for this case, just about all filesystems will be faster with one directory as 
they can just do a sequential walk through the directory.

2. open file 22,987

for this case you will see a drastic difference between different filesystems 
(and potentially even the same filesystem with different options). For example, 
this will be very slow on Ext2, or on Ext3 without hashdir enabled. It's 
supposed to be much faster on Ext3 with hashdir, but I've had mixed results when 
I've tried it. On the other hand this is a very fast operation on XFS.

David Lang

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