[xquery-talk] performance figures for xquery processors

Michael Kay mhk at mhk.me.uk
Wed Feb 8 09:51:29 PST 2006

> In my laptop, Saxon can't load 100M xml document.
> it is because memory space (total 768M/free about 250M) is 
> insufficient, but it'll scaling topic. That was why I put 
> the issue.

How much memory did you allocate to the Java VM? Usually -Xmx512M -Xms512M
should be sufficient for a 100Mb document, though if the processing is
non-trivial it would be better to allocate more.
> Object creation is still heavy even in latest JVM 
> and each Object has at least 8 bytes! memory footprint, 
> this costs.

This is why Saxon doesn't represent nodes of the tree using objects. The
memory used by the tinytree is about 20bytes per node plus 2 bytes per
character of text and attribute content. Attribute-intensive documents may
take more space because attribute values are held as String objects.

Michael Kay

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