This book constitutes thoroughly reviewed and selected short papers presented at the 25th East-European Conference on Advances in Databases and Information Systems, ADBIS 2021, as well as papers presented at doctoral consortium and ADBIS 2021 workshops. Due to the COVID-19 the conference and satellite events were held in hybrid mode. The 11 full papers and 18 short papers were carefully reviewed and selected from 97 total submissions. This volume presents the papers that have been accepted for the following satellite events: Workshop on Intelligent Data - From Data to Knowledge, DOING 2021; International Symposium on Data-Driven Process Discovery and Analysis, SIMPDA 2021; Workshop on Modern Approaches in Data Engineering and Information System Design, MADEISD 2021; Workshop on Advances in Data Systems Management, Engineering, and Analytics, MegaData 2021; Workshop on Computational Aspects of Network Science, CAoNS 2021; Doctoral Consortium.

This book constitutes the proceedings of the 25th European Conference on Advances in Databases and Information Systems, ADBIS 2021, held in Tartu, Estonia, in August 2021. The 18 full papers presented together with 3 keynotes were carefully reviewed and selected from 70 submissions. The selected papers span a wide spectrum of topics in databases and related technologies, tackling challenging problems and presenting inventive and efficient solutions. They are organized in 5 sessions: patterns and events, social media and text mining, indexes, queries and constraints, high-dimensional data and data streams, and data integration.