From: Martin Langhoff <martin.langhoff@gmail.com>
Date: Fri, 07 Sep 2007 00:33:57 GMT
Subject: Re: Git's database structure
Message-ID: <46a038f90709061733s3b8f15b7se3e4002c1f69a04d@mail.gmail.com>
In-Reply-To: <9e4733910709050912i57ed7137o6abb02ee741d394b@mail.gmail.com>

On 9/6/07, Jon Smirl <jonsmirl@gmail.com> wrote:
> Use blame for an example. Blame has to crawl every commit to see if it

Sure. Build a quick dedicated index for that and measure

 - cost (size and commit/fetch costs)
 - benefit
 - frequency of usage

git is a special-purpouse DB that does great for certain access
patterns. Have a look at monotone for a design that looks a lot like
git but is backed by a general purpouse DB and does equally poorly for
all access patterns ;-)

> It keeps doing this until it figures out the last
> author for every line in the file. Worse case blame has to crawl every
> commit in the data store.

Yep. Can we get a minimal-cost index with just enough hints that can
speed up blame, and perhaps git log with/very/deep/path? Probably!

That's worth pursuing sure.


martin