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Re: question: Increasing factor for XML vs Binary

From: Mike Champion <mc@xegesis.org>
Date: 18 Nov 2004 11:58:37 -0500
To: public-xml-binary@w3.org
Message-ID: <E1CUpcK-0001rz-Dc@frink.w3.org>


Yes, I just became aware if this appriach yesterday at Michael LeventhalLs talk at XML 2004.  IIRC he indicated that he knew of no studies applying it to XML.

I can see this as very valuable in certain scenarios, but U need help envisioning how it could be a generic binary XML format.
-----Original Message-----
From:  Stephen D. Williams
Date:  11/18/04 11:43 am
To:  Mike Champion 
Cc:  Silvia.De.Castro.Garcia@esa.int,  public-xml-binary@w3.org
Subj:  Re: question: Increasing factor for XML vs Binary

One thing that is missing from a lot of these analyses is what could be 
saved by being able to do deltas.  In a situation where there is any 
kind of repetition such as protocol messages (in XMPP), records of some 
kind in a stream or file, or a request/response, the ability to send 
only what's different efficiently may use less CPU and be more efficient 
than even schema-based solutions.

I plan to benchmark and demonstrate this kind of solution soon.  There 
is a way to use the idea of a delta in a way that is very schema-like, 
but isn't so firmly tied to a schema.  Use in a 'header compression' 
style is even more powerful although it is somewhat more entangled in 
the semantics of the application.

sdw

Mike Champion wrote:

>
>Sigh most of that was lost somewhere ... I'm on a handheld ...
>
>I'll interperet this as 'how much of a compression factor can be achieved by using a binary vs XML encoding of the same data.'  The usual answer, I'm afraid: it depends.  As best I recall from a literature survey:
>
>larger docs compress better than small,
>
>you can get more compression if you use more CPU (and hence battery) power,
>
>you can get very good compression if you assume that the schema is known to both sides and docs are valid instances,.
>
>My recollection is that 5:1 compression is realistic for arbitrary XML and 10:1 and higher is feasible with shared schemas.
>
>
>-----Original Message-----
>From:  Silvia.De.Castro.Garcia@esa.int
>Date:  11/4/04 8:56 am
>To:  public-xml-binary@w3.org
>Subj:  question: Increasing factor for XML vs Binary 
>
>Hi all,
>        I would like to know the estimation order of the increasing factor 
>for the XML format respect to the equivalent binary product, I mean, which 
>is the order of the overload that will supose using XML instead of binary 
>format?
>
>Thank you very much,
>Best regards,
>
>Silvia de Castro.
>
>
>  
>


-- 
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Stephen D. Williams 703-724-0118W 703-995-0407Fax 20147-4622 AIM: sdw
Received on Thursday, 18 November 2004 16:58:44 GMT

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