Today, I will tell about the current status and latest novelties of XQuery. We will start with briefly touching it’s history to review its original scope, followed by a description of various of XQueries extensions. Some of the latest proposals will come by. We will also explore the territories beyond its original scope.

1. XQuery Novelties
Geert Josten
Hardcore XML track
XML Holland
11 november 2010

2. Agenda
 Original Scope
 Extending Scope
 Newest Extensions
 Beyond Scope
 Summary
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3. about XQuery
“XQuery is replacing proprietary middleware
languages and Web Application
development languages.”
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4. About XQuery
“XQuery is replacing proprietary middleware
languages and Web Application
development languages.”
 Observation, glue
 More and more XQuery applications
 Beyond original scope
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5. Original scope
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6. Origin
 1999, XPath and XSLT not enough
 Query languages applied to XML
 SQL, OQL, Lorel, ..  XML-QL, XQL
XQuery
 Merged into Quilt
 XQuery WD in 2001
XQuery
XQuery
XQuery
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7. Origin
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8. Extending scope
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9. Database features
 Efficient storage and extraction  XQuery 1.0
 Searching
 Transactional updating
 Data integrity, Triggers
 Simultaneous access
 Security, Crash-recovery
 Optionally: Versioning
 ...
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10. XQuery and XPath Full Text 1.0
 First extension, 2004
 W3C Candidate Recommendation
 Search within specific nodes
 Advanced „contains‟ expressions
 Options
• stemming, wildcards, thesaurus, ...
 Relevance ranking
 Lot of implementations, few compliant
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11. XQuery Update Facility 1.0
 Introduced in 2006
 W3C Candidate Recommendation
 Updating of individual nodes:
 insert, delete, replace, rename, and transform
 No return values!
 Various implementations, partly compliant
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12. Newest extensions
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13. XQuery Data Definition Facility
 Presented at XML Prague 2010
 28msec and ETH Zürich
 Static declaration:
 collections, indexes and constraints
 Functions:
 Updating collections
 Probing indexes
 One implementation?
 Zorba / Sausalito
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14. Update (PUL) compositions
 Presented at XML Prague 2010
 ETH Zürich and Oracle
 Storage cheap
 Keep all changes
 Consolidated changes aka composition
 Versions integral part of tree
 No implementations?
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15. Beyond scope
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16. XQuery Scripting Extension 1.0 (SX)
 W3C Working Draft since 2008
 Procedural constructs
 While, variable assignment, exit, ..
 Breaks functional approach
 Also allows multiple, incremental updates
 Update *and* return results
 Very useful for application logic
 Few implementations yet
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17. XQuery 1.1
 W3C Working Draft since 2008
 Lots of „small‟ improvements
 Improved FLWOR
 Try/Catch
 Output declarations
 Dynamic function invocation
 Mature language, design patterns
 Not many implementations yet
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18. XRX and NoSQL
 NoSQL:
 Use non-relational database
 Open source or open standard (like XQuery)
 XRX:
 Xforms + Rest + Xquery
 Innovative two-tier architecture
 XForms front-end, XQuery back-end,
REST api
 Breaking long-lasting traditions
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19. Summary
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20. Database features revisited
 Features covered:
 Extraction, Searching, Updating, Data constraints,
Versioning
 Functional in nature
 Uncovered:
 Storage, Security, Triggers, Crash-recovery..
 Mostly technical, necessary?
 More lacking?
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21. Just remember
XQuery is not just for querying XML!
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22. Questions?
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23. Further reading
 W3C:
 http://www.w3.org/XML/Query/
 http://www.w3.org/standards/techs/xquery
 XML Prague:
 http://www.xmlprague.cz/2010/index.html
 http://www.zorba-
xquery.com/downloads/xmlprague/papers/pulcomposition.pdf
 http://download.28msec.com/sausalito/technical_reading/xqddf.pdf
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24. Timeline
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25. XQuery and XPath Full Text 1.0 example
Contains expression
for $b in /books/book Combined search
where $b/title
contains text "improving“ ftand "usability“
ordered distance at most 2 words at start
return
Advanced search criterium
$b
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26. XQuery Data Definition Facility example
declare collection users as element()*;
declare automatically maintained index users-by-id
on nodes xqddf:collection( xs:QName(“users") )
by @id as xs:string;
xqddf:insert-nodes(
xs:QName(“users"), <user id=“geert”/> );
xqddf:probe-index-point(
xs:QName(“users-by-id"), “geert” );
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