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Re: "Binary XML" proposals
- From: "Stephen D. Williams" <firstname.lastname@example.org>
- To: Tim Bray <email@example.com>
- Date: Tue, 10 Apr 2001 15:23:47 -0400
Tim Bray wrote:
> At 12:22 PM 08/04/01 +0600, Danny Ayers wrote:
> > Ok, so if you put all this together,
> >what would you be gaining? Say an order or two of magnitude of speed? (and
> >the same kind of gains for data storage)
> The world may have a place for binary XML, but the above is not an
> argument for it. First of all, an argument that unpacking a
> binary format (particularly on a machine whose binaries are
> different and you have to bit-swizzle) is significantly faster than
> XML parsing a la expat or MSXML, needs to supported by actual
> empirical data rather than by assertion. And suppose, as a thought
> experiment, that this were true; if you were to speed up the
> XML parsing/generating part of an XML-using application, how much
> would that speed up the whole application? You'd need to know
> what proportion of its time it spends parsing/generating XML. In
> some apps, this proportion is going to be very small.
I have been working, off and on, on a binary structured XML format that
solves a number of problems at once. Application speed is indeed a
primary focus of what I'm doing.
The problem is that parsing and production of XML involve large amounts
of memory allocation, copying, and pointer following of data with
extremely poor locality of reference.
These and related problems make using XML at least somewhat expensive,
and in some business applications this overhead comes to dominiate all
processing being done.
> As for the data storage volume issue, uh, isn't the world awash
> in admirable compression technology that works pretty well on
> most data formats, and particularly well on redundant textual
> stuff like XML?
> Absent some good strong empirical evidence, neither processing
> nor storage cost are a priori arguments for going binary.
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Stephen D. Williams
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