This volume constitutes the thoroughly refereed post-conference proceedings of the Sixth International Symposium on Foundations of Information and Knowledge Systems (FoIKS 2010) which was held in Sofia, Bulgaria, in February 2010. The 19 revised full papers presented together with three invited talks were carefully reviewed and selected from 50 papers.

This volume contains the papers presented at the “Second International S- posium on Foundations of Information and Knowledge Systems” (FoIKS 2002), which was held in Schloß Salzau, Germany from February 20th to 23rd, 2002. FoIKS is a biennial event focusing on theoretical foundations of information and knowledge systems. It aims to bring together researchers working on the theoretical foundations of information and knowledge systems and to attract researchers working in mathematical ?elds such as discrete mathematics, c- binatorics, logics, and ?nite model theory who are interested in applying their theories to research on database and knowledge base theory. FoIKS took up the tradition of the conference series “Mathematical Fundamentals of Database S- tems” (MFDBS) which enabled East-West collaboration in the ?eld of database theory. The ?rst FoIKS symposium was held in Burg, Spreewald (Germany) in 2000. Former MFDBS conferences were held in Dresden (Germany) in 1987, Visegr ́ ad (Hungary) in 1989, and in Rostock (Germany) in 1991. Proceedings of these previous events were published by Springer-Verlag as volumes 305, 364, 495, and 1762 of the LNCS series. In addition the FoIKS symposium is intended to be a forum for intensive d- cussions. For this reason the time slot of long and short contributions is 60 and 30 minutes respectively, followed by 30 and 15 minutes for discussions, respectively. Furthermore, participants are asked in advance to prepare as correspondents to a contribution of another author. There are also special sessions for the pres- tation and discussion of open research problems.

This book constitutes the refereed proceedings of the 10th International Symposium on Foundations of Information and Knowledge Systems, FoIKS 2018, held in Budapest, Hungary, in May 2018.The 20 revised full papers presented together with 1 invited talk were carefully reviewed and selected from 40 submissions. The papers address various topics such as big data; database design; dynamics of information; information fusion; integrity and constraint management; intelligent agents; knowledge discovery and information retrieval; knowledge representation, reasoning and planning; logics in databases and AI; mathematical foundations; security in information and knowledge systems; semi-structured data and XML; social computing; the semantic web and knowledge management; and the world wide web.​

This book constitutes the refereed proceedings of the 11th International Symposium on Foundations of Information and Knowledge Systems, FoIKS 2020, held in Dortmund, Germany, in February 2020. The 19 revised full papers presented were carefully reviewed and selected from 33 submissions. The papers address various topics such as big data; database design; dynamics of information; information fusion; integrity and constraint management; intelligent agents; knowledge discovery and information retrieval; knowledge representation, reasoning and planning; logics in databases and AI; mathematical foundations; security in information and knowledge systems; semi-structured data and XML; social computing; the semantic web and knowledge management; and the world wide web.​

This book constitutes the proceedings of the 8th International Symposium on Foundations of Information and Knowledge Systems, FoIKS 2014, held in Bordeaux, France, in March 2014. The 14 revised full papers presented together with 5 revised short papers and two invited talks were carefully reviewed and selected from 52 submissions. The papers address various topics such as database design, dynamics of information, information fusion, integrity and constraint management, intelligent agents, knowledge discovery and information retrieval, knowledge representation, reasoning and planning, logics in databases and AI, mathematical foundations, security in information and knowledge Systems, semi-structured data and XML, social computing, the semantic Web and knowledge management as well as the WWW.