Re: Git is not scalable with too many refs/*

From: NAKAMURA Takumi <geek4civic@gmail.com>
Date: Jun 10, 2011, 03:59 UTC
Message-ID: <BANLkTimEGjBMrbQpkZfWYPTZ93syiKFHdw@mail.gmail.com>
In-Reply-To: <20110609162604.GC25885@sigill.intra.peff.net>

Good afternoon Git! Thank you guys to give me comments.

Jakub and Shawn,

Sure, Notes should be used at the case, I agree.

> (eg. git log --oneline --decorate shows me each svn revision)

My example might misunderstand you. I intended tags could show me pretty abbrev everywhere on Git. I would be happier if tags might be available bi-directional alias, as Stephen mentions.

It would be better git-svn could record metadata into notes, I think, too. :D

Stephen,

2011/6/10 Stephen Bash <bash@genarts.com>:

Show 5 quoted lines

> I've seen two different workflows develop:
>  1) Hacking on some code in Git the programmer finds something wrong.  Using Git tools he can pickaxe/bisect/etc. and find that the problem traces back to a commit imported from Subversion.
>  2) The programmer finds something wrong, asks coworker, coworker says "see bug XYZ", bug XYZ says "Fixed in r20356".
>
> I agree notes is the right answer for (1), but for (2) you really want a cross reference table from Subversion rev number to Git commit.

It is the point I wanted to say, thank you! I am working with svn-men. They often speak svn revision number. (And I have to tell them svn revs then)

> In our office we created the cross reference table once by walking the Git tree and storing it as a file (we had some degenerate cases where one SVN rev mapped to multiple Git commits, but I don't remember the details), but it's not really usable from Git.  Lightweight tags would be an awesome solution (if they worked).  Perhaps a custom subcommand is a reasonable middle ground.

Reconstructing svnrev-commits mapping can be done by git-svn itself. Unfortunately, git-svn's .rev-map is sorted by revision number. I think it would be useless to make subcommands unless they were pluggable into Git as "smart-tag resolver".

Peff,

At first, thank you to work for Github! Awesome! I didn't know Github has refs issues. (yeah, I should not push 100k of tags to Github for now :p )

I am working on linux and windows. Many-refs-repo can make Git awfully slow (than linux!) I hope I could work also for windows to improve various performance issue.

FYI, I have tweaked git-rev-list for commits not to sort by date with --quiet. It improves git-fetch (git-rev-list --not --all) performance when objects is well-packed.

...Takumi