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Re: XML / HTML Transport size

• To: James Clark <jjc@j...>
• Subject: Re: XML / HTML Transport size
• From: Benjamin Franz <snowhare@n...>
• Date: Mon, 18 Nov 2002 07:27:55 -0800 (PST)
• Cc: John Cowan <jcowan@r...>, "Gerben Rampaart (Casnet Mechelen)" <Gerben@C...>, <xml-dev@l...>
• In-reply-to: <139597501.1037649224@[192.168.0.222]>

On Mon, 18 Nov 2002, James Clark wrote:

> 
> > A variety
> > of small-scale studies have shown that general-purpose compression is
> > generally as good as, or better than, some scheme that knows it's
> > compressing XML.
> 
> Hmmm.  What about
> 
>   http://www.research.att.com/sw/tools/xmill/

Nice try - but no cigar.

Using a real file from my office (I chose a nice big one at random to
test):

-rw-rw----    1 snowhare snowhare  7267803 Nov 18 07:15 recipes.xml

xmill returned:

-rw-rw-r--    1 snowhare snowhare  1993131 Nov 18 07:15 recipes.xmi

but a simple bzip2 returned:

-rw-rw----    1 snowhare snowhare  1922919 Nov 18 07:15 recipes.xml.bz2

So, the _optimized_ XML compressor did more poorly than a default general
purpose compressor by a few percentage points (at least for this data).  
Their description sounds remarkably similiar to a block sort compressor -
which is _precisely_ what bzip2 is (minus the 'patent rights' language
from AT&T ;) ). Which is probably why the end sizes are fairly close for
both.

Its _DAMNED HARD_ to improve on a modern general purpose compression
program for textual data.

-- 
Jerry

I should either have been less specific or more correct ...

                ---Andy Armstrong <andy@w...>

• Follow-Ups:
  • Re: XML / HTML Transport size
    • From: "Karl Waclawek" <karl@w...>
  • Re: XML / HTML Transport size
    • From: Robin Berjon <robin.berjon@e...>

• References:
  • Re: XML / HTML Transport size
    • From: James Clark <jjc@j...>

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