@InProceedings{tencate_et_al:LIPIcs.ICDT.2015.161, author = {ten Cate, Balder and Dalmau, Victor}, title = {{The Product Homomorphism Problem and Applications}}, booktitle = {18th International Conference on Database Theory (ICDT 2015)}, pages = {161--176}, series = {Leibniz International Proceedings in Informatics (LIPIcs)}, ISBN = {978-3-939897-79-8}, ISSN = {1868-8969}, year = {2015}, volume = {31}, editor = {Arenas, Marcelo and Ugarte, Mart{\'\i}n}, publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik}, address = {Dagstuhl, Germany}, URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ICDT.2015.161}, URN = {urn:nbn:de:0030-drops-49832}, doi = {10.4230/LIPIcs.ICDT.2015.161}, annote = {Keywords: Homomorphisms, Direct Product, Data Examples, Definability, Conjunctive Queries, Schema Mappings} }