Holistic Twig Joins: Optimal XML Pattern Matching

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Holistic Twig JoinsOptimal XML Pattern Matching

• Written by
• Nicolas Bruno
• Nick Koudas
• Divesh Srivastava
• Presented by
• Jose Luna
• John Bassett

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What is XML?

• Extensible Markup Language
• Tag-based markup language that allows you to
  share structured information
• Information is easily transferred across systems

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XML Example
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Twigs

• A twig is simply a subtree
• Example (ignore numbers for now)

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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.

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XQuery Relationships

• Single line indicates parent-child relationship
• Double line indicates an ancestor-descendent
  relationship

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XQuery Example 1

• Query
• booktitle XML and year 2000
• Associated query tree

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XQuery Example 2

• Query
• booktitle XML//authorfn jane
• AND ln doe
• Associated
• query tree

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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

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XB-Tree Example
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Experimental Results
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Experimental Results
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Experimental Results
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Experimental Results
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Experimental Results
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Experimental Results
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Questions?Thank you!