dynamic allocation file buffer

Paul Boddie paul at boddie.org.uk
Fri Sep 12 11:34:37 CEST 2008


On 12 Sep, 08:30, Steven D'Aprano
<ste... at REMOVE.THIS.cybersource.com.au> wrote:
>
> Which is why I previously said that XML was not well suited for random
> access.

Maybe not. A consideration of other storage formats such as HDF5 might
be appropriate:

http://hdf.ncsa.uiuc.edu/HDF5/whatishdf5.html

There are, of course, HDF5 tools available for Python.

> I think we're starting to be sucked into a vortex of obtuse and opaque
> communication.

I don't know about that. I'm managing to keep up with the discussion.

> We agree that XML can store hierarchical data, and that it
> has to be read and written sequentially, and that whatever the merits of
> castironpi's software, his original use-case of random access to a 4GB
> XML file isn't workable. Yes?

Again, XML specifically might not be workable for random access in a
serialised form, despite people's best efforts at processing it in
various unconventional ways, but that doesn't mean that random access
to a 4GB file containing hierarchical data isn't possible, so I
suppose it depends on whether he is wedded to the idea of using
vanilla XML or not. It's always worth exploring the available
alternatives before embarking on a challenging project, unless one
wants to pursue the exercise as a learning experience, and I therefore
suggest investigating whether HDF5 doesn't already solve at least some
of the problems or use-cases stated in this discussion.

Paul



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