Hello team,
Linus Torvalds made a statement regarding merging/branching and stated (as far as I know) that "creating branch is not the issue, merge is", in context of Subversion/Git.
I do not find the origin source for that. Can you please help and point me to a statement or article where Linus elaborated on this?
Thanks for your help.
Kind regards
Michael
Hello Michael,
On 26/02/2017 12:40, Michael Hüttermann wrote:
Linus Torvalds made a statement regarding merging/branching and stated
(as far as I know) that "creating branch is not the issue, merge is", in
context of Subversion/Git.
I do not find the origin source for that. Can you please help and point
me to a statement or article where Linus elaborated on this?
Could it be that you think of "Tech Talk: Linus Torvalds on Git"[1]
(held on May 3, 2007)?
To give you some clue, here`s an excerpt from Linus' talk/presentation
(taken from the transcript[2] containing the whole thing):
"... Subversion for example, talks very loudly about how they do CVS
right by making branching really cheap. It's probably on their main
webpage where they probably say branching in subversion is O(1)
operation, you can do as many cheap branches as you want. Nevermind
that O(1) is actually with pretty large O I think, but even if it
takes a millionth of a second to do branching, who cares? It's the
wrong thing you are measuring. Nobody is interested in branching,
branches are completely useless unless you merge them, and CVS cannot
merge anything at all. You can merge things once, but because CVS
then forgets what you did, you can never ever merge anything again
without getting horrible horrible conflicts. Merging in subversion is
a complete disaster. The subversion people kind of acknowledge this
and they have a plan, and their plan sucks too. It is incredible how
stupid these people are. They've been looking at the wrong problem
all the time. Branching is not the issue, merging is..."
This specific branch/merge performance talk starts at 50:20[3], where
the part quoted above comes at 51:34[4].
Please note that there`s more context before and after this excerpt
that puts it all into the meant perspective, so you may really want
to watch/listen/read the whole thing anyway.
Regards,
Buga
[1] https://www.youtube.com/watch?v=4XpnKHJAok8
[2] https://git.wiki.kernel.org/index.php/LinusTalk200705Transcript
[3] https://youtu.be/4XpnKHJAok8?t=3020
[4] https://youtu.be/4XpnKHJAok8?t=3094
W dniu 26.02.2017 o 16:19, Igor Djordjevic pisze:
Hello Michael,
On 26/02/2017 12:40, Michael Hüttermann wrote:
quoted
Linus Torvalds made a statement regarding merging/branching and stated
(as far as I know) that "creating branch is not the issue, merge is", in
context of Subversion/Git.
I do not find the origin source for that. Can you please help and point
me to a statement or article where Linus elaborated on this?
Could it be that you think of "Tech Talk: Linus Torvalds on Git"[1]
(held on May 3, 2007)?
To give you some clue, here`s an excerpt from Linus' talk/presentation
(taken from the transcript[2] containing the whole thing):
"... Subversion for example, talks very loudly about how they do CVS
right by making branching really cheap. It's probably on their main
webpage where they probably say branching in subversion is O(1)
operation, you can do as many cheap branches as you want. Nevermind
that O(1) is actually with pretty large O I think, but even if it
takes a millionth of a second to do branching, who cares? It's the
wrong thing you are measuring. Nobody is interested in branching,
branches are completely useless unless you merge them, and CVS cannot
merge anything at all. You can merge things once, but because CVS
then forgets what you did, you can never ever merge anything again
without getting horrible horrible conflicts. Merging in subversion is
a complete disaster. The subversion people kind of acknowledge this
and they have a plan, and their plan sucks too. It is incredible how
stupid these people are. They've been looking at the wrong problem
all the time. Branching is not the issue, merging is..."
This specific branch/merge performance talk starts at 50:20[3], where
the part quoted above comes at 51:34[4].
Note also that while "creating branch is not the issue, merge is"
remains true, modern Subversion (post 1.5) makes merging easy thanks
to svn:mergeinfo property.
Though it does it in completely different way than Git and other
"graph of commits" VCS-es, because of the "branch is directory"
philosophy, namely that it keeps information about what was merged
in, rather than finding common ancestor(s) and using this information
for resolving merge.
Please note that there`s more context before and after this excerpt
that puts it all into the meant perspective, so you may really want
to watch/listen/read the whole thing anyway.
Regards,
Buga
[1] https://www.youtube.com/watch?v=4XpnKHJAok8
[2] https://git.wiki.kernel.org/index.php/LinusTalk200705Transcript
[3] https://youtu.be/4XpnKHJAok8?t=3020
[4] https://youtu.be/4XpnKHJAok8?t=3094