Why is Git better than Subversion?

Question

I've been using Subversion for a few years and after using SourceSafe, I just love Subversion. Combined with TortoiseSVN, I can't really imagine how it could be any better.

Yet there's a growing number of developers claiming that Subversion has problems and that we should be moving to the new breed of distributed version control systems, such as Git.

How does Git improve upon Subversion?

Answer 1

Git also makes branching and merging really easy. Subversion 1.5 just added merge tracking, but Git is still better. With Git branching is very fast and cheap. It makes creating a branch for each new feature more feasible. Oh and Git repositories are very efficient with storage space as compared to Subversion.

Answer 2

Other answers have done a good job of explaining the core features of Git (which are great). But there's also so many little ways that Git behaves better and helps keep my life more sane. Here are some of the little things:

1. Git has a 'clean' command. SVN desperately needs this command, considering how frequently it will dump extra files on your disk.
2. Git has the 'bisect' command. It's nice.
3. SVN creates .svn directories in every single folder (Git only creates one .git directory). Every script you write, and every grep you do, will need to be written to ignore these .svn directories. You also need an entire command ("svn export") just to get a sane copy of your files.
4. In SVN, each file & folder can come from a different revision or branch. At first, it sounds nice to have this freedom. But what this actually means is that there is a million different ways for your local checkout to be completely screwed up. (for example, if "svn switch" fails halfway through, or if you enter a command wrong). And the worst part is: if you ever get into a situation where some of your files are coming from one place, and some of them from another, the "svn status" will tell you that everything is normal. You'll need to do "svn info" on each file/directory to discover how weird things are. If "git status" tells you that things are normal, then you can trust that things really are normal.
5. You have to tell SVN whenever you move or delete something. Git will just figure it out.
6. Ignore semantics are easier in Git. If you ignore a pattern (such as *.pyc), it will be ignored for all subdirectories. (But if you really want to ignore something for just one directory, you can). With SVN, it seems that there is no easy way to ignore a pattern across all subdirectories.
7. Another item involving ignore files. Git makes it possible to have "private" ignore settings (using the file .git/info/exclude), which won't affect anyone else.

Answer 3

It's all about the ease of use/steps required to do something.

If I'm developing a single project on my PC/laptop, git is better, because it is far easier to set up and use. You don't need a server, and you don't need to keep typing repository URL's in when you do merges.

If it were just 2 people, I'd say git is also easier, because you can just push and pull from eachother.

Once you get beyond that though, I'd go for subversion, because at that point you need to set up a 'dedicated' server or location.

You can do this just as well with git as with SVN, but the benefits of git get outweighed by the need to do additional steps to synch with a central server. In SVN you just commit. In git you have to git commit, then git push. The additional step gets annoying simply because you end up doing it so much.

SVN also has the benefit of better GUI tools, however the git ecosystem seems to be catching up quickly, so I wouldn't worry about this in the long term.

Answer 4

This is the wrong question to be asking. It's all too easy to focus on git's warts and formulate an argument about why subversion is ostensibly better, at least for some use cases. The fact that git was originally designed as a low-level version control construction set and has a baroque linux-developer-oriented interface makes it easier for the holy wars to gain traction and perceived legitimacy. Git proponents bang the drum with millions of workflow advantages, which svn guys proclaim unnecessary. Pretty soon the whole debate is framed as centralized vs distributed, which serves the interests of the enterprise svn tool community. These companies, which typically put out the most convincing articles about subversion's superiority in the enterprise, are dependent on the perceived insecurity of git and the enterprise-readiness of svn for the long-term success of their products.

But here's the problem: Subversion is an architectural dead-end.

Whereas you can take git and build a centralized subversion replacement quite easily, despite being around for more than twice as long svn has never been able to get even basic merge-tracking working anywhere near as well as it does in git. One basic reason for this is the design decision to make branches the same as directories. I don't know why they went this way originally, it certainly makes partial checkouts very simple. Unfortunately it also makes it impossible to track history properly. Now obviously you are supposed to use subversion repository layout conventions to separate branches from regular directories, and svn uses some heuristics to make things work for the daily use cases. But all this is just papering over a very poor and limiting low-level design decision. Being able to a do a repository-wise diff (rather than directory-wise diff) is basic and critical functionality for a version control system, and greatly simplifies the internals, making it possible to build smarter and useful features on top of it. You can see in the amount of effort that has been put into extending subversion, and yet how far behind it is from the current crop of modern VCSes in terms of fundamental operations like merge resolution.

Now here's my heart-felt and agnostic advice for anyone who still believes Subversion is good enough for the foreseeable future:

Subversion will never catch up to the newer breeds of VCSes that have learned from the mistakes of RCS and CVS; it is a technical impossibility unless they retool the repository model from the ground up, but then it wouldn't really be svn would it? Regardless of how much you think you don't the capabilities of a modern VCS, your ignorance will not protect you from the Subversion's pitfalls, many of which are situations that are impossible or easily resolved in other systems.

It is extremely rare that the technical inferiority of a solution is so clear-cut as it is with svn, certainly I would never state such an opinion about win-vs-linux or emacs-vs-vi, but in this case it is so clearcut, and source control is such a fundamental tool in the developer's arsenal, that I feel it must be stated unequivocally. Regardless of the requirement to use svn for organizational reasons, I implore all svn users not to let their logical mind construct a false belief that more modern VCSes are only useful for large open-source projects. Regardless of the nature of your development work, if you are a programmer, you will be a more effective programmer if you learn how to use better-designed VCSes, whether it be Git, Mercurial, Darcs, or many others.

Answer 5

I like Git because it actually helps communication developer to developer on a medium to large team. As a distributed version control system, through its push/pull system, it helps developers to create a source code eco-system which helps to manage a large pool of developers working on a single project.

For example say you trust 5 developers and only pull codes from their repository. Each of those developers has their own trust network from where they pull codes. Thus the development is based on that trust fabric of developers where code responsibility is shared among the development community.

Of course there are other benefits which are mentioned in other answers here.

Answer 6

First, concurrent version control seems like an easy problem to solve. It's not at all. Anyway...

SVN is quite non-intuitive. Git is even worse. [sarcastic-speculation] This might be because developers, that like hard problems like concurrent version control, don't have much interest in making a good UI. [/sarcastic-speculation]

SVN supporters think they don't need a distributed version-control system. I thought that too. But now that we use Git exclusively, I'm a believer. Now version control works for me AND the team/project instead of just working for the project. When I need a branch, I branch. Sometimes it's a branch that has a corresponding branch on the server, and sometimes it does not. Not to mention all the other advantages that I'll have to go study up on (thanks in part to the arcane and absurd lack of UI that is a modern version control system).