Lessons from PostgreSQL's Git transition

Posted Oct 12, 2010 21:23 UTC (Tue) by ballombe (subscriber, #9523)
Parent article: Lessons from PostgreSQL's Git transition

> The community verdict was to wait for one version control system to become the clear leader. In retrospect, this turned out to have been a good decision.

This article rather shows the opposite. If they had switched to SVN in 2007, they would have been in a far better position to switch to git now, both technically and socially.

Lessons from PostgreSQL's Git transition

Posted Oct 12, 2010 21:43 UTC (Tue) by knan (subscriber, #3940) [Link]

And you base that opinion on what, exactly?

Lessons from PostgreSQL's Git transition

Posted Oct 12, 2010 21:45 UTC (Tue) by jberkus (guest, #55561) [Link] (6 responses)

On the contrary:

a) If we had migrated to SVN in 2007, we'd probably wouldn't migrate to git or anything else until 2012, or later.

b) We'd as likely have gone to Monotone or Arch. And then we'd be in trouble now ... we'd end up supporting that project just so we could continue to use it.

c) I don't see any way in which we'd be "in a far better position to switch to git now, both technically and socially." SVN is just CVS++.

Lessons from PostgreSQL's Git transition

Posted Oct 12, 2010 23:08 UTC (Tue) by brouhaha (subscriber, #1698) [Link] (5 responses)

Subversion has a much better designed repository ("filesystem") that doesn't tend to accumulate a bunch of bizarre cruft the way CVS does. Exporting a repository from Subversion and importing it into another source control system is *much* easier than doing it from CVS.

That said, I don't think that using Subversion as an intermediate step for a few years would have helped that much.

It does sound, though, like you're trying to force Git to act like a centralized VCS. If that's really what you want, I don't think Git was the right choice.

Lessons from PostgreSQL's Git transition

Posted Oct 12, 2010 23:16 UTC (Tue) by daglwn (guest, #65432) [Link]

Git is a fine choice for a centralized VCS. One can easily use it with the CVS/SVN model. The mistake is throwing away use of git's automated merging tools and doing it by hand. That's no better than CVS.

Lessons from PostgreSQL's Git transition

Posted Oct 13, 2010 2:42 UTC (Wed) by yarikoptic (guest, #36795) [Link] (1 responses)

just my blunt 0.1 cents: SVN imho rests on an analogy which, at first sight, is user-friendly; but it impairs mind clarity to absorb the main notion of DVCS such as git and hg later on -- it is 'branch is just a directory, you can copy it'. CVS is closer to the notion of GIT/HG branches since there they still live in a "hyperspace" and are appreciated as such.

on the other hand, git-svn is such a handy tool with its bidirectional flow, that it makes "transition" much easier, whenever people could develop entirely in git and commit back to SVN.

Altogether, I think that direct jump CVS -> GIT was the right route; it could be only better if done earlier ;)

Lessons from PostgreSQL's Git transition

Posted Oct 13, 2010 11:50 UTC (Wed) by marcH (subscriber, #57642) [Link]

Subversion tagging and branching (or rather: the lack of) is indeed a regression compared to CVS:

<http://en.wikipedia.org/wiki/Apache_Subversion#Subversion...>

With Subversion you basically end up having to manage tags manually in some external document. For fun search the Subversion mailing lists: you will find numerous people explaining how convenient is the lack of tags!

Lessons from PostgreSQL's Git transition

Posted Oct 13, 2010 9:34 UTC (Wed) by cmot (guest, #53097) [Link]

| That said, I don't think that using Subversion as an intermediate step for a
| few years would have helped that much.

Remember that a big chunk of the conversion was in the support infrastructure. Having to revamp the buildfarm etc. infrastructure twice wouldn't have helped.

(I don't know the situation in the pg universe, but in Debian, quite a few administrators of support infrastructure are not intimately involved in development, so they may not see the ideas behind a change that means quite a lot of work to them...)

Lessons from PostgreSQL's Git transition

Posted Oct 21, 2010 14:15 UTC (Thu) by jnareb (subscriber, #46500) [Link]

> Subversion has a much better designed repository ("filesystem") that
> doesn't tend to accumulate a bunch of bizarre cruft the way CVS does.
> Exporting a repository from Subversion and importing it into another source
> control system is *much* easier than doing it from CVS.

Unfortunately because of "branches are folders" idea, with non-enforced
convention for being in repository hierarchy, makes it easy to screw up
repository in bizzare ways... differently than CVS, but as badly.

Those mishandled SVN repositories are PITA to import to Git.