@InProceedings{doleschal_et_al:LIPIcs.ICDT.2021.10, author = {Doleschal, Johannes and Bratman, Noa and Kimelfeld, Benny and Martens, Wim}, title = {{The Complexity of Aggregates over Extractions by Regular Expressions}}, booktitle = {24th International Conference on Database Theory (ICDT 2021)}, pages = {10:1--10:20}, series = {Leibniz International Proceedings in Informatics (LIPIcs)}, ISBN = {978-3-95977-179-5}, ISSN = {1868-8969}, year = {2021}, volume = {186}, editor = {Yi, Ke and Wei, Zhewei}, publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik}, address = {Dagstuhl, Germany}, URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ICDT.2021.10}, URN = {urn:nbn:de:0030-drops-137181}, doi = {10.4230/LIPIcs.ICDT.2021.10}, annote = {Keywords: Information extraction, document spanners, regular expressions, aggregation functions} }