Re: [xml-dev] Performance comparisons of tree models

[Mike Sokolov <sokolov@ifactory.com>]

On 09/12/2012 01:19 PM, Michael Kay wrote:
> I have been doing some performance comparisons of different Java XML 
> tree models, as used by Saxon, and the results may be of general 
> interest:
>
> http://dev.saxonica.com/blog/mike/2012/09/index.html#000194
>
> Of course, this is a measurement of one particular workload and the 
> results may not extrapolate to other workloads.
>
> Michael Kay
> Saxonica
>
What a coincidence ... I have just this week been doing a performance 
comparison that is somewhat similar to that.

I compared Saxon TinyTree with JDOM's XPath 1.0 implementation in a 
common use case for our platform: mapping XML documents to Java entity 
objects.  I did find a substantial improvement using TinyTree, although 
nothing like the amount that you demonstrate.  Our test involves running 
a large number of independent XPath expressions.  These expressions are 
typically simple, involving one or two child steps and mostly no 
function calls.

I saw a 30-40% improvement moving from Saxon to JDOM (so JDOM numbers 
about 1.5 on the scale in your blog post).

I'm not sure why the numbers are at such a variance to those you report, 
but there are a number of differences between what we've done that could 
explain it: I used JDOM XPath with JDOM Documents; I guess it might be 
interesting to compare Saxon XPath.  Also, the expressions we tested 
were extremely simple, and it seems likely that differences are less 
noticeable in that case.

At any rate, the difference is significant enough that we will 
definitely be moving towards switching our data model to TinyTree.  I 
expect to see additional gains beyond what I've measured due to lowered 
memory footprint, and we have not yet measured any impact on XSLT 
performance, which should also improve substantially based on what you 
report.

-Mike Sokolov