MIX: A Meta-Data Indexing System for XML

SungRan Cho, L3S Nick Koudas, University of Toronto Divesh Srivastava, AT&T Labs-Research

Motivation  Diverse information over the Web quality (e.g., accuracy, recency), security  Queryable for meta-data with underlying data  Annotate XML data with a variety of meta-data  Efficiently identify data that meet desired constraints on meta-data

Our Meta-data Model  Meta-data levels - Assigned to elements by associating an attribute  One-sided range constraint - find all sales with approximation error < 5% - update timestamp > 2005-Jan-01 - find senate documents with security level < `secret`  Inheritance - A meta-data level is automatically inherited by its sub elements unless explicitly specified

MDI (Meta-data Indexes)  Develop a family of Meta-data Indexes Multi-dimensional index structure  Features of Meta-data Indexes Actual meta-data levels Inherited meta-data levels Inheritance source nodes

MIX (Meta-data Indexing for XML)  Meta-data indexed querying Support for all XPath axes  Dynamic maintenance of meta-data Add, delete, change

Architecture of MIX

MDI Management Meta-data Specification Bulk Load Index Maintenance Meta-data change XML Stores MDI XPath Querying Meta-data threshold Execution Engine Query Result

Thank you