1. Priorisation in Segmentation of XML Documents
Distributed XML:
Priorisation in Segmentation of XML Documents
Markus Ylikerälä
Sampsa Toivanen

2. Motivation Increasing market of mobile devices
Rapid development of hardware
Limited bandwidth
Data sharing with peer-to-peer (P2P) technology

3. Problem
“Why would someone like to consume his or her mobile host's battery and pay for the use of bandwidth for someone else?”

4. Framework

5. Objective
XML Document

6. Focus XStream Our focus is to improve the XStream
Segmentates XML tree in level-order
Speeds up data transmission over bad quality wireless connections
Our focus is to improve the XStream
Priorisation of XML elements
More versatile tree traversal schemes

7. A Simple Example
The effect of priorisation on the waiting queue

8. Another Example
A subtree is processed before continuing the default level-order traversal

9. Priorisation Priorities are assigned to elements using metadata
XPath is used to specify a set of elements
Priority values range from –Inf to Inf
Mapping between element sets and priority values

10. Potential Uses Benefits yielded by priorisation vary
Priorisation is useful for
Highly structural XML documents
Large XML documents
Poor connections

11. Use Case: SVG Scalable Vector Graphics (SVG)
W3C Recommendation for representing vector graphics in XML
Large file sizes
Grouping of elements
Currently in use, waiting for a breakthrough

12. Future Work
Implementation
Evaluation
Comparison with Xstream

13. Conclusions Improvement of distributing XML documents to mobile hosts
Our XML Priorisation enhances Xstream
Evaluation is still needed