Re: Why SHA are 40 bytes? (aka looking for flames)

From: Nicolas Pitre <nico@cam.org>
Date: Apr 24, 2007, 15:04 UTC
Message-ID: <alpine.LFD.0.98.0704241058490.12375@xanadu.home>
In-Reply-To: <462E18C8.4070001@op5.se>

On Tue, 24 Apr 2007, Andreas Ericsson wrote:

> Using a more efficient compression algorithm for the objects 
> themselves (bzip2, anyone?) will most likely reduce storage size an 
> order of magnitude more than reducing the size of the hash, although 
> at the expense of CPU-efficiency.

An order of magnitude I really doubt it. Maybe 20% could be a really optimistic prediction. But if bzip2 could reduce the repo by 20%, it will slow runtime usage of that repo by maybe 100%. That is not worth it.

This is also the reason why we changed the default zlib compression level from "best" to "default".

Nicolas