Requirements and Challenges for Query Execution across Decentralized Environments

In Companion Proceedings of the ACM Web Conference 2024 (2024)

Due to the economic and societal problems being caused by the Web’s growing centralization, there is an increasing interest in decentralizing data on the Web. This decentralization does however cause a number of technical challenges. If we want to give users in decentralized environments the same level of user experience as they are used to with centralized applications, we need solutions to these challenges. We discuss how query engines can act as layer between applications on the one hand, and decentralized environments on the other hand, Query engines therefore act as an abstraction layer that hides the complexities of decentralized data management for application developers. In this article, we outline the requirements for query engines over decentralized environments. Furthermore, we show how existing approaches meet these requirements, and which challenges remain. As such, this article offers a high-level overview of a roadmap in the query and decentralization research domains.