Cart
[Home] [By Thread] [By Date] [Recent Entries]
Hi Elena, It's under "Comparing DTD and XML Schema Validation Performance" : 8<----8<----8<----8<----8<----8<----8<----8<----8<---- With Xerces, validating against an XML Schema is more expensive than validating against an equivalent DTD. When no validation is performed, using XML Schema appears to be more performant than using DTD. This is due to the fact that in that particular implementation of Xerces (1.4.4), the XML Schema referenced in the input document is not even read (as revealed by monitoring the calls to the EntityResolver). The XML Schema instance document is therefore treated as a DTD-less document (since there is not even a Document Type Declaration - DOCTYPE). When running the benchmark with a more recent version of Xerces (2.0b4), when no validation is performed, using XML Schema is less performant than using DTD, quasi-mirroring the results obtained when validating. In that particular instance, monitoring the calls to the EntityResolver showed that the XML Schema was indeed loaded and parsed. Incidentally, we can also notice a sensible improvement of performance with this newer version of Xerces. 8<----8<----8<----8<----8<----8<----8<----8<----8<---- The "bug", or at least unwanted behaviour, is that even if no validation is performed, the XML Schema is loaded and parsed. I don't know if this has a big impact on performance, yet I think the problem would have been easily dismissed if the parsing and validating layers where clearly separated. Anyway, from what you say, they are separated (though I don't understand why such a bug would exist, then). I read a part of the documentation you pointed us to and I like the clean component system. What I don't like, though, is that all this composition system takes place "under the hood", with a custom interface (XNI), the whole system being hidden under the main parsing API (JAXP). I think this system should be fully outside of the parser, that is to say I think the parser should not be the main API, but a part of a bigger system. Think it as a kind of opposition between XNI under the hood and JAXP as a public interface vs. JAXP for parsing and something like SAX filters or XPipe to build processing pipelines. Maybe there are reasons that makes the XNI approach more interesting, I have to do further reading on the XNI doc, but intuitively I prefer an approach where processing takes place outside of the parser rather than inside. Regards, Nicolas >-----Message d'origine----- >De : Elena Litani [mailto:elitani@c...] >Envoye : mercredi 13 mars 2002 20:09 >A : Nicolas LEHUEN >Objet : Re: Java Technology and XML : API benchmark > > >Nicolas LEHUEN wrote: >> >> So the bug reported by the article from Sun has been fixed since ? > >To what bug you are referring..? I did not think I saw any.. > >-- >Elena Litani / IBM Toronto >
|
