Re: Achieving efficient storage of weirdly structured repos

From: Jakub Narebski <jnareb@gmail.com>
Date: Apr 4, 2008, 06:21 UTC
Message-ID: <m3tziita2y.fsf@localhost.localdomain>
In-Reply-To: <alpine.LFD.1.00.0804031402530.14670@woody.linux-foundation.org>

Linus Torvalds <torvalds@linux-foundation.org> writes:

Show 17 quoted lines

> On Thu, 3 Apr 2008, Roman Shaposhnik wrote:
>> 
>> The last item (trees) also seem to take the most space and the most 
>> reasonable explanation that I can offer is that NetBeans repository has 
>> a really weird structure where they have approximately 700 (yes, seven 
>> hundred!) top-level subdirectories there. They are clearly 
>> Submodules-shy, but that's another issue that I will need to address 
>> with them.
> 
> Trees taking the biggest amount of space is not unheard of, and it may 
> also be that the name heuristics (for finding good packing partners) could 
> be failign, which would result in a much bigger pack than necessary. 
> 
> So if you already did an aggressive repack like the above, I'd happily 
> take a look at whether maybe it's bad heuristics for finding tree objects 
> to pair up for delta-compression. Do you have a place where you can put 
> that repo for people to clone and look at?

Hmmm... I wonder if it would be the case that would speed-up development of pack v4. If I remember correctly one of bigger changes was the way trees were represented in pack; the biggest improvement was for trees.

One of bigger hindrances, as I understand it, in developing pack v4 was the fact that it didn't offer that much of improvement in typical cases for the work needed... but perhaps "your" repository would be good showcase for pack v4.

Just my 2 eurocents...

-- 
Jakub Narebski
Poland
ShadeHawk on #git