Distributed Database Systems: The Case for NewSQL -- Boosting OLTP Performance using Write-back Client-side Caches -- pygrametl: A Powerful Programming Framework for Easy Creation and Testing of ETL Flows -- A Data Warehouse of Wi-Fi Sessions for Contact Tracing and Outbreak Investigation -- Convergence Proof for Actor-Critic Methods Applied to PPO and RUDDER -- Revival of MAS Technologies in Industry -- From Strategy to Code: Achieving Strategical Alignment in Software Development Projects through Conceptual Modelling -- On State-Level Architecture of Digital Government Ecosystems: From ICT-Driven to Data-Centric.

The LNCS journal Transactions on Large-Scale Data- and Knowledge-Centered Systems focuses on data management, knowledge discovery, and knowledge processing, which are core and hot topics in computer science. Since the 1990s, the Internet has become the main driving force behind application development in all domains. An increase in the demand for resource sharing (e.g., computing resources, services, metadata, data sources) across different sites connected through networks has led to an evolution of data- and knowledge management systems from centralized systems to decentralized systems enabling large-scale distributed applications providing high scalability. This, the 48th issue of Transactions on Large-Scale Data- and Knowledge-Centered Systems, contains 8 invited papers dedicated to the memory of Prof. Dr. Roland Wagner. The topics covered include distributed database systems, NewSQL, scalable transaction management, strong consistency, caches, data warehouse, ETL, reinforcement learning, stochastic approximation, multi-agent systems, ontology, model-driven development, organisational modelling, digital government, new institutional economics and data governance.