Sebastian Skritek
Senior Lecturer Dipl.-Ing. Dr.techn.
Research Focus
- Logic and Computation: 100%
Research Areas
- Semantic Web, Database Theory, Databases
Role
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Senior Lecturer
Databases and Artificial Intelligence, E192-02
Courses
2022W
- Bachelor Thesis / 184.691 / PR
- Foundations of Information Systems / 192.104 / VU
- Fundamentals of Data Analysis and Visualization / 192.103 / VU
- Fundamentals of Digital Systems / 192.134 / VU
- Project in Computer Science 1 / 184.688 / PR
- Project in Computer Science 2 / 184.689 / PR
2023S
- Bachelor Thesis / 184.691 / PR
- Data Base Systems / 184.686 / VU
- Fundamentals of programming and algorithms / 192.097 / VU
- Project in Computer Science 1 / 184.688 / PR
- Project in Computer Science 2 / 184.689 / PR
Projects
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Selbstlernende Prognose kapazitiver Aufwände zur Sicherung der Materialver- und -entsorgung komplexer Produktionssysteme
2018 – 2022 / Austrian Research Promotion Agency (FFG) -
SEE: SPARQL Evaluation and Extensions
2012 – 2016 / Vienna Science and Technology Fund (WWTF) / Publications: 160846, 160883, 163693, 163857, 58571, 58647, 58730, 58731, 58791, 58861, 59083, 59147, 59164, 59165, 59177, 59562, 59563, 59564, 59566, 59675, 59676, 59677, 59681, 59683, 59708, 59710, 59743, 59748, 59773, 59864, 59878, 59879, 59880, 59881, 59882, 59885, 59887, 59890, 60189, 60277, 60328, 60329, 60331, 60334, 60335, 60336, 60338, 60339, 60449, 62617, 62621, 62622, 62623, 62624, 62625, 62626, 90722, 90829 -
Service-Oriented Data Integration
2009 – 2013 / Vienna Science and Technology Fund (WWTF) / Publications: 163468, 163619, 163721, 163857, 171521, 171669, 171818, 174914, 56346, 56390, 56471, 56477, 56999, 57002, 57013, 57113, 57344, 57345, 57362, 57372, 57504, 57563, 57564, 57566, 57768, 57828, 57830, 57849, 57855, 58268, 58571, 89803, 89904 -
Theoretical Tractability vs. Practical Computation
2008 – 2012 / Austrian Science Fund (FWF) / Publications: 163468, 163619, 163857, 171669, 171670, 175369, 40665, 56407, 56408, 56422, 56424, 56425, 56427, 56428, 56801, 56837, 57341, 57345, 57833, 57859, 57860, 57862, 57883, 58571
Publications
Note: Due to the rollout of TU Wien’s new publication database, the list below may be slightly outdated. Once the migration is complete, everything will be up to date again.
2020
- Characterizing Tractability of Simple Well-Designed Pattern Trees with Projection. / Skritek, S., & Mengel, S. (2020). Characterizing Tractability of Simple Well-Designed Pattern Trees with Projection. Theory of Computing Systems, 65(1), 3–41. https://doi.org/10.1007/s00224-020-10002-z
- Enumerating the Repairs of Inconsistent Databases / Kimmelfeld, B., Pichler, R., Kolaitis, P. G., & Skritek, S. (2020). Enumerating the Repairs of Inconsistent Databases. WEPA 2020 - 4th International Workshop on Enumeration Problems and Applications, online, EU. http://hdl.handle.net/20.500.12708/87117
2019
- A complexity theory for hard enumeration problems / Creignou, N., Kröll, M., Pichler, R., Skritek, S., & Vollmer, H. (2019). A complexity theory for hard enumeration problems. Discrete Applied Mathematics, 268, 191–209. https://doi.org/10.1016/j.dam.2019.02.025 / Project: HyperTrac
- Characterizing Tractability of Simple Well-Designed Pattern Trees with Projection / Skritek, S., & Mengel, S. (2019). Characterizing Tractability of Simple Well-Designed Pattern Trees with Projection. In 22nd International Conference on Database Theory, {ICDT} 2019 (pp. 20:1-20:18). Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik. https://doi.org/10.4230/LIPIcs.ICDT.2019.20 / Project: HyperTrac
- Towards Reconciling Certain Answers and {SPARQL:} Bag Semantics to the Rescue? / Skritek, S. (2019). Towards Reconciling Certain Answers and {SPARQL:} Bag Semantics to the Rescue? In Proceedings of the 13th Alberto Mendelzon International Workshop on Foundations of Data Management, Asunci{’{o}}n, Paraguay, June 3-7, 2019 (pp. 1–5). CEUR-WS.org. http://hdl.handle.net/20.500.12708/57864 / Project: HyperTrac
2018
- Efficient Evaluation and Static Analysis for Well-Designed Pattern Trees with Projection / Kröll, M., Barcelo, P., Pichler, R., & Skritek, S. (2018). Efficient Evaluation and Static Analysis for Well-Designed Pattern Trees with Projection. ACM Transactions on Database Systems, 43(2), 1–44. https://doi.org/10.1145/3233983
2017
- On the Complexity of Hard Enumeration Problems / Creignou, N., Kröll, M., Pichler, R., Skritek, S., & Vollmer, H. (2017). On the Complexity of Hard Enumeration Problems. In Language and Automata Theory and Applications - 11th International Conference, LATA 2017 (pp. 183–195). http://hdl.handle.net/20.500.12708/57056 / Projects: FAIR, HINT
2016
- On the Complexity of Enumerating the Answers to Well-Designed Pattern Trees / Kröll, M., Pichler, R., & Skritek, S. (2016). On the Complexity of Enumerating the Answers to Well-Designed Pattern Trees. In R. Pichler & A. S. da Silva (Eds.), Proceedings of the 10th Alberto Mendelzon International Workshop on Foundations of Data Management, Panama City, Panama, May 8-10, 2016 (p. 5). CEUR Workshop Proceedings. http://hdl.handle.net/20.500.12708/56490 / Projects: HINT, SEE
- The Challenge of Optional Matching in SPARQL / Ahmetaj, S., Fischl, W., Kröll, M., Pichler, R., Šimkus, M., & Skritek, S. (2016). The Challenge of Optional Matching in SPARQL. In M. Gyssens & G. R. Simari (Eds.), Lecture Notes in Computer Science (pp. 169–190). Lecture Notes in Computer Science (LNCS) / Springer. https://doi.org/10.1007/978-3-319-30024-5_10 / Projects: HINT, SEE
- On the Complexity of Enumerating the Answers to Well-designed Pattern Trees / Kröll, M., Pichler, R., & Skritek, S. (2016). On the Complexity of Enumerating the Answers to Well-designed Pattern Trees. In W. Martens & T. Zeume (Eds.), 19th International Conference on Database Theory, ICDT 2016, Bordeaux, France, March 15-18, 2016 (pp. 1–18). Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik. https://doi.org/10.4230/LIPIcs.ICDT.2016.22 / Projects: HINT, SEE
2015
- Towards Reconciling SPARQL and Certain Answers / Ahmetaj, S., Fischl, W., Pichler, R., Šimkus, M., & Skritek, S. (2015). Towards Reconciling SPARQL and Certain Answers. In A. Gangemi, L. Stefano, & A. Panconesi (Eds.), Proceedings of the 24th International Conference on World Wide Web. ACM. https://doi.org/10.1145/2736277.2741636 / Projects: HINT, SEE
- Efficient Evaluation and Approximation of Well-designed Pattern Trees / Barcelo, P., Pichler, R., & Skritek, S. (2015). Efficient Evaluation and Approximation of Well-designed Pattern Trees. In T. Milo & D. Calvanese (Eds.), Proceedings of the 34th ACM SIGMOD-SIGACT-SIGAI Symposium on Principles of Database Systems. ACM. https://doi.org/10.1145/2745754.2745767 / Projects: HINT, SEE
- Towards Reconciling SPARQL and Certain Answers (Extended Abstract) / Ahmetaj, S., Fischl, W., Pichler, R., Simkus, M., & Skritek, S. (2015). Towards Reconciling SPARQL and Certain Answers (Extended Abstract). In A. Cali & M.-E. Vidal (Eds.), Proceedings of the 9th Alberto Mendelzon International Workshop on Foundations of Data Management, Lima, Peru, May 6 - 8, 2015 (p. 6). CEUR Workshop Proceedings. http://hdl.handle.net/20.500.12708/56096 / Projects: HINT, SEE
- Efficient Evaluation of Well-designed Pattern Trees (Extended Abstract) / Barceló, P., Pichler, R., & Skritek, S. (2015). Efficient Evaluation of Well-designed Pattern Trees (Extended Abstract). In A. Cali & M.-E. Vidal (Eds.), Proceedings of the 9th Alberto Mendelzon International Workshop on Foundations of Data Management, Lima, Peru, May 6 - 8, 2015 (p. 6). CEUR Workshop Proceedings. http://hdl.handle.net/20.500.12708/56095 / Projects: HINT, SEE
- DL-Lite and Conjunctive Queries Extended by Optional Matching / Ahmetaj, S., Fischl, W., Pichler, R., Simkus, M., & Skritek, S. (2015). DL-Lite and Conjunctive Queries Extended by Optional Matching. In D. Calvanese & B. Konev (Eds.), Proceedings of the 28th International Workshop on Description Logics, Athens,Greece, June 7-10, 2015 (p. 4). CEUR Workshop Proceedings. http://hdl.handle.net/20.500.12708/56094 / Projects: HINT, SEE
2014
- Containment and equivalence of well-designed SPARQL / Pichler, R., & Skritek, S. (2014). Containment and equivalence of well-designed SPARQL. In R. Hull & M. Grohe (Eds.), Proceedings of the 33rd ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems. ACM. https://doi.org/10.1145/2594538.2594542 / Project: SEE
- On the Hardness of Counting the Solutions of SPARQL Queries / Pichler, R., & Skritek, S. (2014). On the Hardness of Counting the Solutions of SPARQL Queries. In G. Gottlob & J. Perez (Eds.), Proceedings of the 8th Alberto Mendelzon Workshop on Foundations of Data Management (p. 6). CEUR-WS. http://hdl.handle.net/20.500.12708/55783 / Project: SEE
- Benchmarking Database Systems for Graph Pattern Matching / Pobiedina, N., Rümmele, S., Skritek, S., & Werthner, H. (2014). Benchmarking Database Systems for Graph Pattern Matching. In Lecture Notes in Computer Science (pp. 226–241). Springer Verlag. https://doi.org/10.1007/978-3-319-10073-9_18 / Project: SEE
2013
- Foundational aspects of Semantic Web optimization : new algorithms and complexity results / Skritek, S. (2013). Foundational aspects of Semantic Web optimization : new algorithms and complexity results [Dissertation, Technische Universität Wien]. reposiTUm. http://hdl.handle.net/20.500.12708/159695
- Static Analysis and Optimization of Semantic Web Queries / Letelier, A., Pérez, J., Pichler, R., & Skritek, S. (2013). Static Analysis and Optimization of Semantic Web Queries. ACM Transactions on Database Systems, 38(4), 1–45. https://doi.org/10.1145/2500130 / Projects: SEE, SODI, TTPC
- Complexity of redundancy detection on RDF graphs in the presence of rules, constraints, and queries / Pichler, R., Polleres, A., Skritek, S., & Woltran, S. (2013). Complexity of redundancy detection on RDF graphs in the presence of rules, constraints, and queries. Semantic Web: Interoperability, Usability, Applicability, 4(4), 351–393. http://hdl.handle.net/20.500.12708/155572 / Projects: SODI, TTPC
- Tractable counting of the answers to conjunctive queries / Pichler, R., & Skritek, S. (2013). Tractable counting of the answers to conjunctive queries. Journal of Computer and System Sciences, 79(6), 984–1001. https://doi.org/10.1016/j.jcss.2013.01.012 / Projects: SODI, TTPC
- Efficient Updates of Uncertain Databases / Hubmer, A., Pichler, R., Savenkov, V., & Skritek, S. (2013). Efficient Updates of Uncertain Databases. In L. Bravo & M. Lenzerini (Eds.), Proceedings of the 7th Alberto Mendelzon International Workshop on Foundations of Data Management Puebla/Cholula, Mexico, May 21-23, 2013 (p. 7). CEUR-WS. http://hdl.handle.net/20.500.12708/54797 / Project: HINT
- Peer Data Management / Roth, A., & Skritek, S. (2013). Peer Data Management. In P. G. Kolaitis, M. Lenzerini, & N. Schweikardt (Eds.), Data Exchange, Integration, and Streams (p. 30). Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, Germany. https://doi.org/10.4230/DFU.Vol5.10452.185 / Projects: SEE, SODI, TTPC
2012
- SPAM: A SPARQL Analysis and Manipulation Tool / Letelier, A., Perez, J., Pichler, R., & Skritek, S. (2012). SPAM: A SPARQL Analysis and Manipulation Tool. In Z. M. Özsoyoglu (Ed.), Proceedings of the VLDB (pp. 1958–1961). http://hdl.handle.net/20.500.12708/54495
- Foundational aspects of semantic web optimization / Skritek, S. (2012). Foundational aspects of semantic web optimization. In X. L. Dong & M. T. Özsu (Eds.), Proceedings of the on SIGMOD/PODS 2012 PhD Symposium - PhD ’12. ACM Press. https://doi.org/10.1145/2213598.2213611
- Static analysis and optimization of semantic web queries / Letelier, A., Pérez, J., Pichler, R., & Skritek, S. (2012). Static analysis and optimization of semantic web queries. In M. Benedikt, M. Krötzsch, & M. Lenzerini (Eds.), Proceedings of the 31st symposium on Principles of Database Systems - PODS ’12. ACM. https://doi.org/10.1145/2213556.2213572 / Project: SODI
2011
- Tractable Counting of the Answers to Conjunctive Queries / Pichler, R., & Skritek, S. (2011). Tractable Counting of the Answers to Conjunctive Queries. In P. Barceló & V. Tannen (Eds.), CEUR Workshop Proceedings (p. 12). CEUR Workshop Proceedings. http://hdl.handle.net/20.500.12708/53692 / Project: SODI
- The Complexity of Evaluating Tuple Generating Dependencies / Pichler, R., & Skritek, S. (2011). The Complexity of Evaluating Tuple Generating Dependencies. In T. Milo (Ed.), Proceedings of the 14#^{th} International Conference on Database Theory (p. 12). ACM. http://hdl.handle.net/20.500.12708/53675 / Projects: SODI, TTPC
2010
- Theory of Peer Data Management / Skritek, S. (2010). Theory of Peer Data Management. Data Exchange, Integration, and Streams (DEIS’10), Schloß Dagstuhl, Deutschland, EU. http://hdl.handle.net/20.500.12708/85055
- Uncertain Databases in Collaborative Data Management / Pichler, R., Savenkov, V., Skritek, S., & Truong, H.-L. (2010). Uncertain Databases in Collaborative Data Management. In A. de Keijzer & M. van Keulen (Eds.), CTIT Workshop Proceedings Series (pp. 129–143). CTIT, Centre for Telematics and Information Technology. http://hdl.handle.net/20.500.12708/53505
- Redundancy Elimination on RDF Graphs in the Presence of Rules, Constraints, and Queries / Pichler, R., Polleres, A., Skritek, S., & Woltran, S. (2010). Redundancy Elimination on RDF Graphs in the Presence of Rules, Constraints, and Queries. In P. Hitzler & T. Lukasiewicz (Eds.), Web Reasoning and Rule Systems (pp. 133–148). Lecture Notes/ Springer. https://doi.org/10.1007/978-3-642-15918-3_11
- Minimising RDF Graphs under Rules and Constraints Revisited / Pichler, R., Polleres, A., Skritek, S., & Woltran, S. (2010). Minimising RDF Graphs under Rules and Constraints Revisited. In A. H. F. Laender & L. V. S. Lakshmanan (Eds.), Proceedings of the 4th Alberto Mendelzon International Workshop on Foundations of Data Management. CEUR Workshop Proceedings. http://hdl.handle.net/20.500.12708/53438
- Implementing a Peer Database Management System / Skritek, S., & Pichler, R. (2010). Implementing a Peer Database Management System. In H. Kaiser & R. Kirner (Eds.), Proceedings of the Junior Scientist Conference 2010 (pp. 299–300). http://hdl.handle.net/20.500.12708/53422
2009
- Implementing a Peer Data Management System / Skritek, S. (2009). Implementing a Peer Data Management System [Diploma Thesis, Technische Universität Wien]. reposiTUm. https://resolver.obvsg.at/urn:nbn:at:at-ubtuw:1-36716
Supervisions
Note: Due to the rollout of TU Wien’s new publication database, the list below may be slightly outdated. Once the migration is complete, everything will be up to date again.
- Generating Diverse Solutions to Conjunctive Queries and Propositional Formulae / Merkl, T. (2022). Generating Diverse Solutions to Conjunctive Queries and Propositional Formulae [Diploma Thesis, Technische Universität Wien]. reposiTUm. https://doi.org/10.34726/hss.2022.102520
- Applying machine learning for processing time prediction for inbound shipments / Eichhorner, F. (2021). Applying machine learning for processing time prediction for inbound shipments [Diploma Thesis, Technische Universität Wien]. reposiTUm. https://doi.org/10.34726/hss.2021.84964
- Complexity of well-designed SPARQL / Svozil, A. (2016). Complexity of well-designed SPARQL [Diploma Thesis, Technische Universität Wien]. reposiTUm. https://doi.org/10.34726/hss.2016.37350