1. Holistic Twig Joins: Optimal XML Pattern Matching
Written by:
Nicolas Bruno
Nick Koudas
Divesh Srivastava
Presented by:
Jose Luna
John Bassett

2. What is XML? Extensible Markup Language
Tag-based markup language that allows you to share structured information
Information is easily transferred across systems

3. XML Example

4. Twigs
A twig is simply a subtree
Example (ignore numbers for now):

5. What is XQuery?
Query language designed to query collections of XML data
XQuery is a full-fledged query language, but we are only concerned with ancestor-descendent and parent-child relationships.

6. XQuery Relationships Single line indicates parent-child relationship
Double line indicates an ancestor-descendent relationship

7. XQuery Example 1 Query: Associated query tree:
book[title = ‘XML’ and year = ‘2000’]
Associated query tree:

8. XQuery Example 2 Query: Associated query tree:
book[title = ‘XML’]//author[fn = ‘jane’
AND ln = ‘doe’]
Associated
query tree:

10. XB-Trees
An XB-Tree is simply a B-Tree that is designed to index this XML data using the positional data
Indexing using (LeftPos : RightPos)
Querying is done just as is done in a regular B-Tree

11. XB-Tree Example

12. Experimental Results

13. Experimental Results

14. Experimental Results

15. Experimental Results

16. Experimental Results

17. Experimental Results

18. Questions? Thank you!