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> Git has no file object, it versions the repo, not files. As someone who has used (in a professional setting) version control systems ranging from RCA to SVN

> Git has no file object, it versions the repo, not files. As someone who has used (in a professional setting) version control systems ranging from RCA to SVN to the current crop (git, mercurial, even darcs), the fact that git versions the repository as a whole instead of individual files is a godsend. You've not known hell until you've had to deal with an RCA/CVS repository with 15+ years of history and thousands of files, each that maintains their own version history (and associated version number!). I'd gladly take the comparative "slowness" of git when dealing with large repositories. > Git is basically a tarball server. Calling that a source management system is an enormous stretch. What, in your opinion, is the definition of a version control system then?

luckydude 9y ago
A version control system is an accurate audit trail of everything that has happened in the repository. Every create, delete, rename, every rwx mode change, every content change. In BitKeeper files work like they do in Unix, there is a (globally) unique name for each file object. Where the object lives in the repository is an attribute of that object, as are the contents, the permissions, who has changed etc. Here's a super common workflow that's easy in BitKeeper and miserable in Git. I'm debugging an assert. I want to see who added the assert. I pop into the gui that shows me the per file graph and contents, search for the assert, hover over the rev and see that it was done a long time ago. I look in the area above the assert and I see a recent change, hover over that, see the comments and go "hmm, maybe this". Double click that line and I pop into a different gui that shows me the whole commit that contains that suspect line. Note that because I have a graph per file, I have checkin comments per file. More work for you poor committers but a godsend for us debuggers. More breadcrumbs are more better. In Git, less breadcrumbs, single commit message. Git wants to go from the rev to the commit, it's miserable to look around in a file and then go backwards to the commit. When I was supporting BitKeeper our average response time to bug report or a crash report was 25 minute. 24x7. The only reason it was that long was because we were all in North America so there was a window where we were all asleep. Response time 6am-6pm PST was typically under 5 minutes. And I credit the fact that the tool accurately recorded everything and you could find the history really easily. Oh, and it didn't slow down as the repo got big. Git is fine in little repos but it sucks pretty hard in big ones. Sucks even worse if you are on NFS. I can dig up benchmarks, we built up a synthetic 4M file repo and ran a bunch of tests on it (it was a modified version of the facebook repo builder, the facebook one had some stuff in it that made Git look incredibly bad, we looked at that and decided that wasn't real world or fair, we took that part out).
- philipwhiuk 9y ago
  > In Git, less breadcrumbs, single commit message. Git wants to go from the rev to the commit, it's miserable to look around in a file and then go backwards to the commit. Less, better breadcrumbs, yes.
  - luckydude 9y ago
    A thought not universally shared. Intel was our biggest customer and when they saw the quality of the breadcrumbs produced by our gui check in tool vs the command line checkins they were smart enough to push hard that everyone used the guis. I get why, as a dev, you want git commit -m'Fixed bug' but as the debugger guy, the reviewer gui, anyone who reads the code, that's a horrible thing to do to those readers. Who, if you wait long enough, will be you. And I'll laugh my ass off at all the lazy committers who really could use more breadcrumbs when they have to debug their code later. Been there, done that, I haven't worked with people that lazy in decades. edit: since HN won't let me extend the thread, let me reply to the comment below because BK does do something special. The GUI for checkins presents you with a list of files, a place to type comments, and a big pane that shows the diffs. You type in comments for the first file, go to the next, type in comments (yes, there is a way to say use the previous comments). As you move from file to file, the bottom pane shows the diffs for that file so you can see what changed in that file. The special sauce, that Git most definitely does not have, is when you get to the last file, which in BK is the ChangeSet file, this is where you would type the commit message. What are the diffs? There aren't any so we stuff all the comments you just typed on individual files. What does that do? Well, on the files you are usually typing in details of how you did this or that, when you get to all of those comments, you naturally uplevel and type in why you were doing all that. It dramatically increases the usefulness of commit messages. That's why Intel pretty much mandated the use of the gui checkin vs the command line checkin.
    - kadenshep 9y ago
      To anyone reading, bitkeeper does nothing special in this regard. Enforce commit message standards, plenty of platforms and systems built around git (and literally every other SCM) have support for this. Here's what he's taking about: http://www.bitkeeper.org/man/citool.html http://www.bitkeeper.org/man/citool.html and http://www.bitkeeper.org/man/templates.html http://www.bitkeeper.org/man/templates.html Here is git's analogous feature: https://robots.thoughtbot.com/better-commit-messages-with-a-gitmessage-template https://robots.thoughtbot.com/better-commit-messages-with-a-... It's possibly the least interesting and least unique selling point an SCM can have. It's really funny that you keep bringing up this example around the thread. EDIT: To respond to the above edit: Again, he's Proving The Point. Commits should be atomic. If you have to individually comment on file changes then the correct thing to do would be to put those in their own commit, no? I'm not really sure what's being described is necessarily a cool feature, but rather a way to avoid making sure your changes are truly related. I honestly don't see the point. This seems like a feature that was written because of the decisions that were made into how BitKeeper works internally, not because it's a fantastic idea. You can get the same thing with atomic commits in git. You comment per file, because BK tracks changes per file. Git does not do this. You should be making your commits atomic because git is tracking the actual content. Atomic commits will accurately describe what's being changed, and then of course those all get lumped together in a patch/PR. Git isn't lacking the feature you're describing, it just kind of is there without any extra data tracking required, because it's not making up for technical design decisions.
hermitdev 9y ago
> As someone who has used (in a professional setting) version control systems ranging from RCA to SVN to the current crop (git, mercurial, even darcs), the fact that git versions the repository as a whole instead of individual files is a godsend. This. A thousand times this. A change isn't a single file, it's likely a changeset of multiple, sometimes hundreds or thousands of files. Most often, you need to know the entire changeset, not just what happened with one file. This is especially true of large-scale refactoring where you're changing the public interface of something. Depending, that can have a far-ranging impact and you want to see that history all together.
- luckydude 9y ago
  You're talking to the guy that created that concept [1]. I get that changesets are cool :) You're right, you do want to see all that info together. But lots of times you want to look at the file view, find the line of code that looks like the problem, and then zoom out to the changeset. BK makes that trivial, Git makes that miserable to impossible. [1] Actually there was a little known system, Aide-de-camp, that one of my people told me about that had changesets so I didn't invent it, but I reinvented it. And made the world aware of the concept. Back when you could search Usenet via dejanews you could search for "changeset" and date limit it to before me talking about it. There were maybe 5 hits. A few years after BK came along there were 100's of thousands of hits. So I wasn't first but I am definitely the reason that you know what a changeset is.
  - plorkyeran 9y ago
    Looking at a file, and then looking the commit which last modified a specific line in that file is a trivial operation in git that I do on a regular basis.
    - luckydude 9y ago
      How long does that take? In BK it's as fast as you can click. If git is like that what tools are you using to do that?
_ph_ 9y ago
SVN does version the whole repository, so a revision can contain any number of changes to files, but it tracks eachs files history too. So a SVN revision is a collection of changes to any number of files/directories.

luckydude 9y ago

A version control system is an accurate audit trail of everything that has happened in the repository. Every create, delete, rename, every rwx mode change, every content change. In BitKeeper files work like they do in Unix, there is a (globally) unique name for each file object. Where the object lives in the repository is an attribute of that object, as are the contents, the permissions, who has changed etc. Here's a super common workflow that's easy in BitKeeper and miserable in Git. I'm debugging an assert. I want to see who added the assert. I pop into the gui that shows me the per file graph and contents, search for the assert, hover over the rev and see that it was done a long time ago. I look in the area above the assert and I see a recent change, hover over that, see the comments and go "hmm, maybe this". Double click that line and I pop into a different gui that shows me the whole commit that contains that suspect line. Note that because I have a graph per file, I have checkin comments per file. More work for you poor committers but a godsend for us debuggers. More breadcrumbs are more better. In Git, less breadcrumbs, single commit message. Git wants to go from the rev to the commit, it's miserable to look around in a file and then go backwards to the commit. When I was supporting BitKeeper our average response time to bug report or a crash report was 25 minute. 24x7. The only reason it was that long was because we were all in North America so there was a window where we were all asleep. Response time 6am-6pm PST was typically under 5 minutes. And I credit the fact that the tool accurately recorded everything and you could find the history really easily. Oh, and it didn't slow down as the repo got big. Git is fine in little repos but it sucks pretty hard in big ones. Sucks even worse if you are on NFS. I can dig up benchmarks, we built up a synthetic 4M file repo and ran a bunch of tests on it (it was a modified version of the facebook repo builder, the facebook one had some stuff in it that made Git look incredibly bad, we looked at that and decided that wasn't real world or fair, we took that part out).

philipwhiuk 9y ago
> In Git, less breadcrumbs, single commit message. Git wants to go from the rev to the commit, it's miserable to look around in a file and then go backwards to the commit. Less, better breadcrumbs, yes.
- luckydude 9y ago
  A thought not universally shared. Intel was our biggest customer and when they saw the quality of the breadcrumbs produced by our gui check in tool vs the command line checkins they were smart enough to push hard that everyone used the guis. I get why, as a dev, you want git commit -m'Fixed bug' but as the debugger guy, the reviewer gui, anyone who reads the code, that's a horrible thing to do to those readers. Who, if you wait long enough, will be you. And I'll laugh my ass off at all the lazy committers who really could use more breadcrumbs when they have to debug their code later. Been there, done that, I haven't worked with people that lazy in decades. edit: since HN won't let me extend the thread, let me reply to the comment below because BK does do something special. The GUI for checkins presents you with a list of files, a place to type comments, and a big pane that shows the diffs. You type in comments for the first file, go to the next, type in comments (yes, there is a way to say use the previous comments). As you move from file to file, the bottom pane shows the diffs for that file so you can see what changed in that file. The special sauce, that Git most definitely does not have, is when you get to the last file, which in BK is the ChangeSet file, this is where you would type the commit message. What are the diffs? There aren't any so we stuff all the comments you just typed on individual files. What does that do? Well, on the files you are usually typing in details of how you did this or that, when you get to all of those comments, you naturally uplevel and type in why you were doing all that. It dramatically increases the usefulness of commit messages. That's why Intel pretty much mandated the use of the gui checkin vs the command line checkin.
  - kadenshep 9y ago
    To anyone reading, bitkeeper does nothing special in this regard. Enforce commit message standards, plenty of platforms and systems built around git (and literally every other SCM) have support for this. Here's what he's taking about: http://www.bitkeeper.org/man/citool.html http://www.bitkeeper.org/man/citool.html and http://www.bitkeeper.org/man/templates.html http://www.bitkeeper.org/man/templates.html Here is git's analogous feature: https://robots.thoughtbot.com/better-commit-messages-with-a-gitmessage-template https://robots.thoughtbot.com/better-commit-messages-with-a-... It's possibly the least interesting and least unique selling point an SCM can have. It's really funny that you keep bringing up this example around the thread. EDIT: To respond to the above edit: Again, he's Proving The Point. Commits should be atomic. If you have to individually comment on file changes then the correct thing to do would be to put those in their own commit, no? I'm not really sure what's being described is necessarily a cool feature, but rather a way to avoid making sure your changes are truly related. I honestly don't see the point. This seems like a feature that was written because of the decisions that were made into how BitKeeper works internally, not because it's a fantastic idea. You can get the same thing with atomic commits in git. You comment per file, because BK tracks changes per file. Git does not do this. You should be making your commits atomic because git is tracking the actual content. Atomic commits will accurately describe what's being changed, and then of course those all get lumped together in a patch/PR. Git isn't lacking the feature you're describing, it just kind of is there without any extra data tracking required, because it's not making up for technical design decisions.

hermitdev 9y ago

> As someone who has used (in a professional setting) version control systems ranging from RCA to SVN to the current crop (git, mercurial, even darcs), the fact that git versions the repository as a whole instead of individual files is a godsend. This. A thousand times this. A change isn't a single file, it's likely a changeset of multiple, sometimes hundreds or thousands of files. Most often, you need to know the entire changeset, not just what happened with one file. This is especially true of large-scale refactoring where you're changing the public interface of something. Depending, that can have a far-ranging impact and you want to see that history all together.

luckydude 9y ago
You're talking to the guy that created that concept [1]. I get that changesets are cool :) You're right, you do want to see all that info together. But lots of times you want to look at the file view, find the line of code that looks like the problem, and then zoom out to the changeset. BK makes that trivial, Git makes that miserable to impossible. [1] Actually there was a little known system, Aide-de-camp, that one of my people told me about that had changesets so I didn't invent it, but I reinvented it. And made the world aware of the concept. Back when you could search Usenet via dejanews you could search for "changeset" and date limit it to before me talking about it. There were maybe 5 hits. A few years after BK came along there were 100's of thousands of hits. So I wasn't first but I am definitely the reason that you know what a changeset is.
- plorkyeran 9y ago
  Looking at a file, and then looking the commit which last modified a specific line in that file is a trivial operation in git that I do on a regular basis.
  - luckydude 9y ago
    How long does that take? In BK it's as fast as you can click. If git is like that what tools are you using to do that?

_ph_ 9y ago

SVN does version the whole repository, so a revision can contain any number of changes to files, but it tracks eachs files history too. So a SVN revision is a collection of changes to any number of files/directories.