Transcript Presentation

An SQI-based gateway to Amazon.com
The ELENA Consortium
http://www.elena-project.org
Information Society
Technologies (ist) PROGRAMME
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Motivation
 Amazon.com offers a large amount of books and
other learning resources
 The content of the repository is available via
Web Services interface
 Content is annotated with (company-specific)
metadata
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Architecture
Wrapper
Amazon.com
(Target
System)
SQI
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Components of the wrapper
QEL Wrapping
Amazon.com
communication
Wrapper
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Implementation Status
 AmazonMessageHandler
– Implemented, tested
 QEL wrapping
– In development
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Amazon query-language
 Keywords (title, author, subject, language, etc.)
 Logical connectors (AND, OR, NOT)
 Parentheses
 Examples:
– (title=‘Faust’) AND (author=‘Goethe’)
– (title=‘Sorstalanság’) AND (author=‘Imre Kertész’) AND
(language=‘hungarian’)
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QEL vs. Amazon query language

QEL has higher expressive power as Amazon query language
– This is a common situation with other systems (like relational database and
SQL)

Question: What to do with queries not expressible in local
query language?
– Same semantics is desirable

Possible strategies:
– reject the query
– Restrict the query (how?)
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