VTD-XML for Large XML Processing

Dealing with a large XML files always become a headache with any DOM based parser , SAX based parsers provide good alternative but need complex programing model and instead of application parser control the flow and support only for forward processing . StAX illuminates some of these issues but not at all ,specially for very large XML files. VTD-XML parser try to be a remedy for those issues with new concept called Virtual Token Descriptor (VTD) that is use 64 bit integers to keep encode offsets, lengths, token types ....etc while original XML file keep intact and undecided. Jimmy Zhang wrote nice article about Non-Extractive Parsing for Xml.com .

VTD-XML basically promise to provide following key features .

1. Conserving memory

   VTD-XML doesn't not create integral data object for XML file . This is relay good enhancement over traditional DOM based parsing.

2. High performance:

3. Incremental update:

4. Xpath support

5. CURD capabilities ..( With efficiency....)
   
   

following four class are the most impotent players of VTD-XML team.

• VTDGen – encapsulate the parsing

• VTDNav – cursor based random access

• AutoPilot – for Xpath support

• XMLModifier – incrementally update XML
  
  

But still VTD-XML does not support for Schema validation and external entities . Those are the main drawbacks of this parser but we can expect these features in near future .

One special tining about VTD-XML , they provide good starting guide and samples so that any one can get familiar within a short period of time .