From: H. Peter Anvin <hpa@zytor.com>
Date: Mon, 05 Sep 2005 18:43:00 GMT
Subject: Re: Moved files and merges
Message-ID: <431C91B4.6040609@zytor.com>
In-Reply-To: <7v4q8z5pqv.fsf@assigned-by-dhcp.cox.net>

Junio C Hamano wrote:
> 
> But previous argument by Linus made in a distant (in git
> timescale) past is now ingrained in my brain: "the additional
> metadata" recorded at the commit time can only help us what we
> envisioned in the past when the tool to record that metadata was
> written.  If we try to "track" by contents, we can do at least
> the same (diff -M being able to tell renames is an example that
> we can get away without having a UUID) and possibly better,
> depending on how much effort we are willing to spend "drilling
> down" when we actually need to know what happened at merge
> time.  What I found most important in that argument by Linus is
> that the "drilling down" algorithm can improve over time while
> "the additional metadata" specification is cast in stone when a
> commit is made.
> 

... unless the "additional metadata" is merely a cache, derived from the 
contents.  The advantage, of course, is that you can produce data that 
is more expensive that way.  On the other hand, if you don't need it, 
it's pointless.

	-hpa