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first let me say i was disappointed that i couldn't get the xml2004
conference into my schedule this year. and the more i read the more
disappointed i am..
everyone's aware that i'm not a fan of binary encodings and some of
those concerns are echoed below. just a few more comments:
1. for wireless etc, the target device (phones, dataloggers, etc)
usually has a slowish processor and real power consumption issues. i
would have thought a lot of research needs to be put into where the
power consumption lies before any choice can be made (cpu cycles vs
transmission cost)
2. in dedicated apps, the generality of xml might not be needed, so
binary and text versions might really be irrelevant
3. moore's law is working, just hard to see sometimes. but back in the
70's and 80's it was difficult to see how digital could provide the
extra bandwidth over analog. now who uses analog - even tv will be soon
all digital - so i think we should consider the impact of moore's law.
4. but here's the real issue: lets call this new thing BML (binary
markup language) so that when the requirements of BML are incompatible
with the requirements of XML - and they surely will be at some stage -
the two standards can gracefully diverge, like another branch in the
evolutionary tree. otherwise one standard must corrupt or restrict the
other at some stage.
rick
Derek Denny-Brown wrote:
>It just isn't possible to be even a single order of magnitude faster in
>the general case. An alternate encoding for XML can provide gains in 2
>ways: file size, or parser CPU usage. I've never seen a format which
>provides significant file size gains without high CPU cost (although you
>can sometimes play games and push all the CPU cost to the writer, so
>that the reader is cheap, for example). Most of the CPU cost of parsing
>is related to the abstract model of XML, not the text parsing: Duplicate
>attribute detection, character checking, namespace resolution/checking.
>Every binary-xml implementation I have researched which improves CPU
>utilization does so by skipping checks such as these. At that point you
>are no longer talking about XML.
>
>Note the key constraint in my opening sentence: "in the general case".
>Some scenarios clearly benefit from an alternate encoding, but different
>scenarios demand different trade-offs. I have yet to hear of any
>proposed solution which successfully balances the different demands.
>I'm not sure it is possible, without creating a homunculus.
>
>-derek
>
>
>
>>-----Original Message-----
>>From: DuCharme, Bob (LNG-CHO) [mailto:bob.ducharme@lexisnexis.com]
>>Sent: Monday, November 22, 2004 12:49 PM
>>To: 'Robin Berjon'; Michael Champion
>>Cc: xml-dev@lists.xml.org
>>Subject: RE: [xml-dev] Hostility to "binary XML" (was Re: [xml-dev]
>>
>>
>XML
>
>
>>2004 weblog items?)
>>
>>Robin Berjon wrote:
>>
>>
>>
>>>Michael Champion wrote:
>>>
>>>
>>>>The 'binary XML' stuff got a lot less hostile reception than I
>>>>expected. Is the world ready to hear that XML 1.x text
>>>>
>>>>
>serialization
>
>
>>>>is not suitable for wireless applications, is this old news, or
>>>>
>>>>
>what?
>
>
>>>during a recent presentation I tried to outrage the audience with
>>>some over-the-top pro-binary XML positions (expecting to use the
>>>push-back to moderate them)
>>>
>>>
>>And in Mike's talk, he did not do this. He put everything I had heard
>>
>>
>in
>
>
>>context, including counter-arguments to the various arguments, so
>>
>>
>there
>
>
>>was
>>little reason to get hostile. For example, there was his point
>>
>>
>(whether
>
>
>>his
>>own or quoting of other people) that just because XML doesn't suit a
>>particular class of applications well doesn't necessarily mean that
>>
>>
>XML
>
>
>>should be twisted inside out to accommodate that class of apps;
>>
>>
>perhaps it
>
>
>>means that that class of apps should look elsewhere for its needs.
>>
>>His answer to my question at the end convinced me to maintain my
>>
>>
>current
>
>
>>level of skepticism: apparently all of the talk of alternative XML
>>encodings
>>being much more efficient than text XML are based on consistent use of
>>document classes for each test, so this consistency means the kind of
>>redundancy that makes compression much easier.
>>
>>When someone prototypes an encoding that is orders of magnitude more
>>efficient for arbitrary XML, which Mike said that no one had done yet,
>>I'll
>>more seriously consider the possibility that a binary XML standard
>>
>>
>might
>
>
>>be
>>worth the trouble.
>>
>>(Mike, please correct me if I misremember. And it was nice to finally
>>
>>
>meet
>
>
>>you!)
>>
>>Bob DuCharme www.snee.com/bob <bob@
>>snee.com> weblog on linking-related topics:
>>http://www.oreillynet.com/pub/au/1191
>>
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>>
>
>
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begin:vcard
fn:Rick Marshall
n:Marshall;Rick
email;internet:rjm@zenucom.com
tel;cell:+61 411 287 530
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