MonetDB/XQuery Technology Preview 1

1
MonetDB/XQuery Technology Preview 1

• Stefan Manegold
• Centrum voor Wiskunde en Informatica
• Amsterdam
• http//monetdb.cwi.nl/ - http//pathfinder-xquer
  y.org/

2
European Pathfinder Team

• CWI, Amsterdam (Netherlands)
• Peter Boncz, Stefan Manegold, Sjoerd Mullender
• University of Twente (Netherlands)
• Maurice van Keulen, Jan Flokstra
• University of Konstanz (Germany)
• Torsten Grust, Jens Teubner, Jan Rittinger

3

Results Performance (1)
XMark benchmark, 110 MB MonetDB/XQuery vs.
X-Hive Galax
4
Results Performance (2)
XMark benchmark, 1.1 GB MonetDB/XQuery vs.
X-Hive
5
Story

• XQuery Example
• Relational XQuery
• System Architecture
• XML Encoding
• Science Reseach
• Scalability
• Outlook
• Conclusions
• Roadmaps
• Release References

6
XQuery Example

• For each author, return number of books and
  receipts
• for books published in the past 2 years, ordered
  by name
• let cat fndoc(www.bn.com/catalog.xml),
  (Documents)
• sales fndoc(www.publishersweekly.com/s
  ales.xml)
• for author in distinct-values(cat//author)
  (Grouping)
• let books cat//book_at_year gt 2003 and
  author author,(Sel.)
• receipts sales/book_at_isbn
  books/_at_isbn/receipts (Join)
• order by author
  (Ordering)
• return
• ltsalesgt (XML
  Construction)
• author
• ltcountgt fncount(books) lt/countgt
  (Aggregation)
• lttotalgt fnsum(receipts) lt/totalgt
• lt/salesgt

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XQuery Example

• For each author, return number of books and
  receipts
• for books published in the past 2 years, ordered
  by name
• let cat fndoc(www.bn.com/catalog.xml),
  ?Documents?
• sales fndoc(www.publishersweekly.com/s
  ales.xml)
• for author in distinct-values(cat//author)
  ?Grouping?
• let books cat//book_at_year gt 2003 and
  author author,?Sel.?
• receipts sales/book_at_isbn
  books/_at_isbn/receipts ?Join?
• order by author
  ?Ordering?
• return
• ltsalesgt ?XML
  Construction?
• author
• ltcountgt fncount(books) lt/countgt
  ?Aggregation?
• lttotalgt fnsum(receipts) lt/totalgt
• lt/salesgt

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XQuery Systems 2 Approaches

• Existing native XML/XQuery systems are built
  from scratch
• Galax, Saxon,
• X-Hive, Tamino,
• (Still have to) re-invent optimization technology
• Our approach
• Build XQuery system on top of an RDBMS
• Leverage mature relational technology
• to achieve efficient XQuery processing

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Architecture
10
XML in an RDBMS XPath Accelerator
xx
ltagt ltbgt ltc/gt lt/bgt ltd/gt
ltegt ltfgt ltg/gt lth/gt
lt/fgt ltigt ltj/gt lt/igt
lt/egt lt/agt
0ltagt 1ltbgt 2ltc/gt lt/bgt 3ltd/gt
4ltegt 5ltfgt 6ltg/gt 7lth/gt
lt/fgt 8ltigt 9ltj/gt lt/igt
lt/egt lt/agt
0ltagt 1ltbgt 2ltc/gt0 lt/bgt1 3ltd/gt2
4ltegt 5ltfgt 6ltg/gt3 7lth/gt4
lt/fgt5 8ltigt 9ltj/gt6
lt/igt7 lt/egt8 lt/agt9
?
?
?
?

• f/following SELECT FROM pre_post WHERE pre gt
  f.pre AND post gt f.post
• f/descendant SELECT FROM pre_post WHERE pre
  gt f.pre AND post lt f.post
• f/preceeding SELECT FROM pre_post WHERE pre
  lt f.pre AND post lt f.post
• f/ancester SELECT FROM pre_post WHERE pre lt
  f.pre AND post gt f.post
• Similar queries for all 13 XPath axes

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Science Research

• More research lead to more optimization
• Join Recognition
• Embedded XPath processing
• Order Awareness
• Various scientific publications

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Results Scalability (3)

• Unsurpassed scalability
• Standard Opteron PC, 8GB RAM, 64-bit Linux
• Can process 11GB documents!
• Mostly linear scaling with document size

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Conclusions

• Relational approach
• Works
• Is fast
• Is scalable
• Crucial Optimizations
• Join recognition
• Embedded XPath processing
• Order awareness
• Research turned into open-source release

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Roadmap

• 30.05.05 MonetDB/XQuery 4.8/0.8 Mercurius
• Developers Release / Technology Preview 1
• 30.09.05 MonetDB/XQuery 4.10/0.10 Venus
• Student Release / Technology Preview 2
• XUpdate, More Optimization
• 30.12.05 MonetDB/XQuery 4.12/1.12 Mars
• Final Release
• Application Programming Interfaces
• End-User Front-Ends

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Open Source Release References

• MonetDB Pathfinder on SourceForge
• Mozilla-like License
• MonetDB homepage
• http//monetdb.cwi.nl/
• Pathfinder homepage
• http//pathfinder-xquery.org/
• Developers website
• http//sf.net/projects/monetdb/

You are welcome to join the MonetDB/XQuery team!