Bridging Different Data Representations Zachary G. Ives University of Pennsylvania CIS 550 – Database & Information Systems October 28, 2003 Some slide content may be courtesy of Susan Davidson, Dan Suciu, & Raghu Ramakrishnan
Administrivia
A Problem
Building a Data Integration System
Typical Data Integration Components
Typical Data Integration Architecture
Challenges of Mapping Schemas
A Few Simple Examples Cust. ID Cust. Name Penn. ID Emp. Name 1234 46732 Ives, Z. Zachary Ives
How Do We Relate Schemas?
Mapping Our Examples Cust. ID Cust. Name Penn. ID Emp. Name 1234 46732 Ives, Z. Zachary Ives
Two Important Approaches
TSIMMIS and Information Manifold
TSIMMIS
Semi-structured Data: OEM
OEM Example
Queries in TSIMMIS
Query Answering in TSIMMIS
A Wrapper Definition in MSL
How to Answer the Query
Query Composition with Views
Matching View Output to Our Query’s Conditions
The Final Step: Unfolding where $x = “Chamberlin” for $b in { for $b in sql(“select * from book where author=‘” + $x +”’”) return <book>$b<author>$x</author></book> }/book where $b/title/text() = “DB 2 UDB” return $b
What Is the Answer? Given schema book(author, year, title) and datalog rules defining an instance: book(“Chamberlin”, “ 1992”, “DB 2 UDB”) book(“Chamberlin”, “ 1995”, “DB 2/CS”)
TSIMMIS
Limitations of TSIMMIS’ Approach
The Information Manifold
Observations of Levy et al.
The Local-as-View Model
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