Re: Binary differencing performs poorly (erractically) on very large text file

Charles Butterfield wrote:
> I have a large text file (around 47 MB) which is a database dump
> (created by msqldump). I periodically commit it to an SVN repo.
> Sometimes the binary differencing works just fine and I get a small
> sized revision in the repo. Other times I get a "full" sized revision
> in the repo, that is revision that is compressed, but essentially the
> same size I get when committing the file to a virgin repo.
>
> Doing a "diff" on the client side files always generates a "relatively"
> small set of differences.

First, why are you talking about "binary" differencing if this is a
text file? See the FAQ entry at [1] although for the purposes of this
question I don't think it really matters.

[1] http://subversion.tigris.org/faq.html#binary-files

Second, FSFS uses a skip-delta approach when storing diffs in the
repository. This is at least partly to improve performance for files
whose revision histories are long. This is probably the cause of what
you are seeing as "inconsistent" diff sizes. See [2].

[2] http://svn.collab.net/repos/svn/trunk/notes/skip-deltas

Cheers,
Raman Gupta

---------------------------------------------------------------------
To unsubscribe, e-mail: users-unsubscribe_at_subversion.tigris.org
For additional commands, e-mail: users-help_at_subversion.tigris.org
Received on 2008-02-16 01:19:13 CET