Re: [h5md-user] attribute modification_time

[Peter Colberg]

On Wed, May 29, 2013 at 11:46:44AM -0400, Peter Colberg wrote:
> On Wed, May 29, 2013 at 05:36:09PM +0200, Felix Höfling wrote:
> > Just some examples:
> > 
> > A user may decide to continue a simulation and to append the results
> > to the same file.
> > 
> > One may want to delete some unneeded data groups after a while (data
> > that should not have been written in the first place).
> 
> Copy. Always copy.
> 
> It is the same rule as with data on a filesystem. When moving large
> collections of files, never move file by file, but always copy
> everything first, and only then remove the old. With HDF5, the
> filesystem becomes the HDF5 file and the files become the groups
> and datasets.

More to the point… One would like to the operation to be atomic.
Thus if operation fails for some reason, it can be repeated.

(Adding to the files example: For some cases, a “move” may already be atomic.)

Peter