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Re: Do long element names impact performance?

• From: David Carlisle <d.p.carlisle@gmail.com>
• To: "Costello, Roger L." <costello@mitre.org>
• Date: Thu, 15 Oct 2015 15:07:34 +0100

On 15 October 2015 at 14:43, Costello, Roger L. <costello@mitre.org> wrote:
> Hi Folks,
>
> Is the following true or false?
>
>         XML developers who fail to grasp the distinction between reading and evaluating
>         an XML instance document may have a good model of the structure of XML,
>         but they usually have a terrible model of the efficiency of processing XML. One
>         XML developer used only one-letter element names, because he felt that it would
>         be faster for the computer to look up one-letter elements than a multi-letter name.
>         While it may be true that shorter names can save a microsecond at read time, this
>         makes no difference at all at evaluation time. Every element, regardless of its name,
>         is just a memory location, and the time to access the location does not depend on the
>         name of the element.
>
> /Roger
>


True of false, depending on the processing being done.

If you have a record of a terabyte of of values stored as
<log>
<n>123</n>
<n>456</n>
...

then changing that to
<Looooooooooooooooooooooog>
<nnnnnnnnnnnnnnnnnnnnnnnnnnn>123</nnnnnnnnnnnnnnnnnnnnnnnnnnn>
<nnnnnnnnnnnnnnnnnnnnnnnnnnn>456</nnnnnnnnnnnnnnnnnnnnnnnnnnn>
...

Is going to increase the filesize by a factor of 6 which might change
download time from 1 hour to 6 hours which isn't "microseconds" but
then again download might use zip compression, or might not or .,...

Even ignoring download, there is no single in memory model for xml so
no general statements can b emade about storage requirements for
element names.

David

• References:
  • Do long element names impact performance?
    • From: "Costello, Roger L." <costello@mitre.org>