Branko,
Trying not to OT but...
On Tue, 2003-03-11 at 19:22, Branko Èibej wrote:
> Tony Mee wrote:
> >Nightmare A - No version control
> > 15 users have their own copies and pass around patches (somehow!)
> > = 15 copies
> >
> >Situation B - CVS
> > 1 master (repository) copy (larger than user copies)
> > + 15 users have their own copies
> > = 16 copies (overhead of 1 admittedly large copy)
> >
> >Situation C - Subversion
> > 1 master (repository) copy (larger than user copies)
> > + 15 users have their own copies
> > + 15 users have their own pristine copy
> > = 31 copies (overhead of more than 200%, ouch)
> >
> Where did you get the >200%? Just comparing the number of copes, 31/16 =
If you're going to pull up a mathematician on calculating percentages
then I guess I'd better respond! Observe situation B... the overhead is
a measure of the overhead of the version management system, relative to
a base case, Nightmare A. Hence for Situation C, 31/15 = 207% or 107% in
excess of Nightmare A.
> 194%. Now, taking into account that the repository is, let's say 10
> times the size of a copy, you get 40/25 = 160%. If your repository is
> 100 times larger (which is more probable, I guess), the factor becomes
> 130/115 = 113%. Not so unreasonable, right?
So we take a repository of 10 times larger than the code it contains.
Situation B) Overhead rate at 25/15 = 167% i.e. 67% in excess of A
Situation C) Overhead rate at 40/15 = 267% i.e. 167% in excess of A
It is interesting that somebody that I assume is pro-Subversion should
choose to make a statement implicitly defining a frame of reference in
which CVS generates no overhead. :)
> >All the diff'ing routines exist, as do all the local file access
> >routines (noting Michael Price's comment) and so do routines for
> >transfering whole files across the network (for the checkout function).
> I detect a possible misconception here. We have two kinds of diffs; the
No I got that bit! I'm not up on your choice of terms yet though and
intended to speak generally of delta/diffs for text and binaries.
> * To remove the need for network access for some operations (such as
> plain "svn diff")
> * To enable the client and server to send deltas to each other
> instead of fulltext versions.
I'd forgotten about the coding for the first bit.
> >So really it's a case of:
~snip~
> Not a problem.
Wow... I didn't expect that. If it's all that easy, maybe it could be
done quickly and in version 1. Now I think I'd better bury my head in
the sand for a bit while I contemplate.
> Some new code, especially in the WC management layer. Which hist happens
> to be the hairyest part of Subversion. :-)
Ah, hairy worms... The worst kind. Eak.
> >Bearing in mind I don't know the code too well (yet). Where is the can
> >of worms kept?
> We have a special climate-controlled room that keeps the worms at a low
> enough temerature so that they remain dormant. If the temperature varies
> by more than +-0.73K, the worms either freeze to death, or eat throught
> the CrTiAl alloy of the airlock doors. Dicey.
Sweet. Do you keep a multitude of pristine working copies too?
tOnY
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Received on Wed Mar 12 17:41:10 2003