Research interests
My main interest has always been in languages for querying data: their design, computational complexity and optimisation. My PhD was about Queries on Graphs, a topic which has seen renewed interest with the advent of the semantic web and social networks. Other areas I have worked in include XML querying, active rule languages (similar to database triggers), deductive rule languages (e.g. Datalog), and compression techniques for XML. Most recently, I have been working on algorithms for combining recommendations from recommender systems as well as a query and transformation language for social network data.
Research projects
Two long-running projects are in the areas of
More recently, I have started working on
Research students
- Khaled Alyoubi (co-supervised with Sven Helmer), working on query optimisation
- Mohammad Jaber (co-supervised with Sven Helmer), working on social networks
- Manizheh Montazerian, working on optimising XML queries
- Petra Selmer (co-supervised with Alex Poulovassilis), working on flexible querying of web data
Recent talks
Automata and Formal Languages slides from a talk on research methods given to graduate students.
The following slides are from talks at recent conferences:
- Query Languages for Graph Databases - invited tutorial at AMW'09 (May 2009)
- XPath Query Satisfiability is in PTIME for Real-World DTDs - XSym'07 (September 2007)
- A Relaxed Approach to RDF Querying - ISWC'06 (November 2006)
- Containment for XPath Fragments under DTD Constraints - ICDT'03 (January 2003)
Recent publications
See also the list of publications from the DBLP Bibliography Server.
- M. Xie, L.V.S. Lakshmanan and P.T. Wood, ``Efficient Top-k Query Answering using Cached Views,'' to appear in Proc. 16th Int. Conf. on Extending Database Technology (EDBT) (March 18-22, Genoa, Italy), 2013.
- P. Barceló, L. Libkin, A.W. Lin and P.T. Wood, ``Expressive Languages for Path Queries over Graph-Structured Data,'' in ACM Trans. on Database Systems, Vol. 37, No. 4, 2012, Article No. 31.
- M. Xie, L.V.S. Lakshmanan and P.T. Wood, ``Composite Recommendations: From Items to Packages,'' in Frontiers of Computer Science, Vol. 6, No. 3, 2012, pp. 264-277.
- P.T. Wood, ``Query Languages for Graph Databases,'' in SIGMOD RECORD, Vol. 41, No. 1 (March), 2012, pp. 50-60.
- A. Poulovassilis, P. Selmer and P.T. Wood, ``Flexible Querying of Lifelong Learner Metadata,'' in IEEE Trans. on Learning Technologies, Vol. 5, No. 2, 2012, pp. 117-129.
- M. Montazerian and P.T. Wood, ``Chasing One's Tail: XPath Containment Under Cyclic DTDs,'' in Proc. 13th International Symposium on Database Programming Languages (August 29, Seattle, Washington), 2011.
- M. Xie, L.V.S. Lakshmanan and P.T. Wood, ``Efficient Rank Join with Aggregation Constraints,'' in Proc. 37th Int. Conf. on Very Large Data Bases (Aug. 29-Sept. 3, Seattle, Washington), PVLDB, Vol. 4, No. 11, 2011, pp. 1201-1212.
- M. San Martín, C. Gutierrez and P.T. Wood, ``SNQL: A Social Network Query and Transformation Language,'' in Proc. 5th Alberto Mendelzon Workshop on Foundations of Data Management (May 9-12, Santiago, Chile), 2011.
- M. Xie, L.V.S. Lakshmanan and P.T. Wood, ``CompRec-Trip: a Composite Recommendation System for Travel Planning,'' demo paper in Proc. 27th IEEE Int. Conf. on Data Engineering (Hannover, Germany, Apr. 11-16), 2011, pp. 1352-1355.
- G. Papamarkos, A. Poulovassilis and P.T. Wood, ``Performance Modelling of Event-Condition-Action Rules in P2P networks,'' in Journal of Computer and System Sciences, DOI: doi:10.1016/j.jcss.2010.02.004, Vol. 77, Elsevier, 2011, pp. 621-636.
- A. Poulovassilis and P.T. Wood, ``Combining Approximation and Relaxation in Semantic Web Path Queries,'' in Proc. 9th International Semantic Web Conference (Shanghai, China, Nov. 7-11), 2010, pp. 631-646.
- M. Xie, L.V.S. Lakshmanan and P.T. Wood, ``Breaking out of the Box of Recommendations: From Items to Packages,'' in Proc. 4th ACM Conf. on Recommender Systems (Barcelona, Spain, Sept. 26-30), 2010, pp. 151-158.
- P. Barceló, C.A. Hurtado, L. Libkin and P.T. Wood, ``Expressive Languages for Path Queries over Graph-Structured Data,'' in Proc. 29th ACM Symposium on Principles of Database Systems (Indianapolis, Indiana, June 6-10), 2010, pp. 3-14.
- P.T. Wood, ``Graph Database,'' in Encyclopedia of Database Systems, Editors-in-chief: M. Tamer Ozsu and Ling Liu, Springer, 2009, pp. 1263-1266.
- C.A. Hurtado, A. Poulovassilis and P.T. Wood, ``Finding Top-k Approximate Answers to Path Queries,'' to appear in Proc. 8th Int. Conf. on Flexible Query Answering Systems (Roskilde, Denmark, Oct. 26-28), 2009.
- C.A. Hurtado, A. Poulovassilis and P.T. Wood, ``Ranking Approximate Answers to Semantic Web Queries,'' in Proc. 6th European Semantic Web Conference (Heraklion, Crete, May 31-June 4), LNCS 5554, Springer-Verlag, 2009, pp. 263-277.
- K. Keenoy, V. Christophides, G. Papamarkos, A. Poulovassilis, D. Kotzinos, P. Rigaux, N. Spyratos, and P.T. Wood, ``Personalisation Services for Self e-Learning Networks,'' in The Learning Grid Handbook: Concepts, Technologies and Applications, S. Salerno, M. Gaeta, P. Ritrovato, N. Capuano, F. Orciouli, S. Miranda and A. Pierri (Editors), IOS Press, February 2008.
- C.A. Hurtado, A. Poulovassilis and P.T. Wood, ``Query Relaxation in RDF,'' Journal on Data Semantics X, LNCS 4900, Springer-Verlag, 2008, pp. 31-61.
- M. Montazerian, P.T. Wood and S.R. Mousavi, ``XPath Query Satisfiability is in PTIME for Real-World DTDs,'' in Proc. Fifth Int. XML Database Symposium (Vienna, Austria, Sept. 23-24), LNCS 4704, Springer-Verlag, 2007, pp. 17-30.
- C.A. Hurtado, A. Poulovassilis and P.T. Wood, ``A Relaxed Approach to RDF Querying,'' in Proc. 5th Int. Semantic Web Conference (Athens, Georgia, Nov. 5-9), LNCS 4273, Springer-Verlag, 2006, pp. 314-328.
- W. Ng, W.-Y. Lam, P.T. Wood and M. Levene, ``XCQ: A Queriable XML Compression System,'' in Knowledge and Information Systems, Vol. 10, No. 4 (November), Springer-Verlag, 2006, pp. 421-452.
- G. Papamarkos, A. Poulovassilis and P.T. Wood, ``Event-Condition-Action Rules on RDF Metadata in P2P Environments,'' in Computer Networks, 50, 10 (July), Elsevier, 2006, pp. 1513-1532.
- A. Poulovassilis, G. Papamarkos and P.T. Wood, ``Event-Condition-Action Rule Languages for the Semantic Web,'' in EDBT Workshops, Reactivity on the Web (Munich, Germany, Mar. 26-31), LNCS 4254, Springer-Verlag, 2006, pp. 855-864.
- K. Keenoy, A. Poulovassilis, V. Christophides, Ph. Rigaux, G. Papamarkos, A. Magkanaraki, M. Stratakis, N. Spyratos, P.T. Wood, ``Personalisation Services for Self e-Learning Networks,'' in Proc. 4th Int. Conference on Web Engineering (Munich, July 26-30), LNCS 3140, Springer-Verlag, 2004, pp. 215-219.
- G. Papamarkos, A. Poulovassilis and P.T. Wood, ``RDFTL : An Event-Condition-Action Language for RDF,'' in Proc. 3rd Int. Workshop on Web Dynamics, at WWW2004 (New York, 18 May), 2004.
- J. Bailey, G. Papamarkos, A. Poulovassilis and P.T. Wood, ``An Event-Condition-Action Language for XML,'' Chapter in Web Dynamics, Springer-Verlag, 2004, pp. 223-248.
- G. Papamarkos, A. Poulovassilis and P.T. Wood, ``Event-Condition-Action Rule Languages for the Semantic Web,'' in Proc. First Int. Workshop on Semantic Web and Databases (Berlin, Germany, Sept. 7-8), 2003, pp. 309-327.
- W.Y. Lam, W. Ng, P.T. Wood and M. Levene, ``XCQ: XML Compression and Querying System,'' in Proc. WWW 2003: Twelfth Int. Conf. on the World Wide Web (Budapest, Hungary, May 20-24), 2003.
- P.T. Wood, ``Containment for XPath Fragments under DTD Constraints,'' in Proc. 9th Int. Conf. on Database Theory (Siena, Italy, Jan. 8-10), LNCS 2572, Springer-Verlag, 2003, pp. 300-314.
Recent programme committee membership
Teaching
- Advances in Data Management (an MSc module)
- Database Management (a BSc/MSc module)
- Internet and Web Technologies (an MSc module)
Short biography
I obtained my BSc and MSc in Computer Science from the University of Cape Town (UCT). I then worked for the Institute for Applied Computer Science at the University of Stellenbosch for 18 months, before leaving for the University of Toronto where I obtained a PhD in Computer Science in 1989. I subsequently spent 9 years as a member of the Department of Computer Science at UCT, before joining the Department of Computer Science at King's College London in 1998. I moved to the School of Computer Science and Information Systems (now Department) at Birkbeck in 2001. I was Head of School from September 2006 until July 2009.