On Wed, 18 Apr 2007, David Berry wrote:
> I'm new to subversion. What are its benefits over CVS?
The main motivator for the JAC is that there is a single repository wide
revision number. If you make a commit the number goes up by one. This
allows you to refer to "revision #5679" and know exactly what state is
being discussed. The pipeline running at CADC will need to know the exact
application state so that it can be stored in the output headers - then if
there is a problem we can easily look at the data files, checkout out
revision XXXX and then investigate (no need to worry about exact times).
In terms of other killer functionality:
- Commits made at the same time are "atomic". This allows related
changes to multiple files to be seen as a single commit (so a single
revision number) - and simplifies revision histories as well as
reverting to earlier revisions for testing (this depends on unrelated
changes being committed separately).
- Directories are understood (so if revision #5679 adds a directory
revision #5678 won't see it - in CVS the directory is there forever
and in all previous revisions)
- Files can be renamed and preserve history (no more painful decision
associated with moving a file - just move it)
- you can edit files off line and still know which files have been
changed and how they have been modified. You can even revert without
the repository being available. (it does this by keeping the unmodified
version around - so you get extra functionality by doubling disk space)
Branches and tags are also easier to do than on CVS.
--
Tim Jenness
JAC software
http://www.jach.hawaii.edu/~timj
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