A Survey on Blockchain Scalability Technologies
TL;DR
This paper reveals that “on-chain basic optimization and off-chain collaborative scaling" has become the mainstream direction of blockchain scalability research, and Directed Acyclic Graphs are highlighted in a separate section, detailing the technical principles and representative systems of three DAG solutions.
Abstract
Blockchain technology, with its features of decentralization, immutability, and traceability, shows broad application potential in fields such as finance, supply chain, and the Internet of Things (IoT). However, as application scenarios expand and the number of users surges, blockchain systems face severe challenges in scalability. Based on the limitations of the traditional single-chain architecture, this paper comprehensively reviews mainstream blockchain scaling solutions from two dimensions: on-chain scaling and off-chain scaling. On-chain scaling covers sharding technology and consensus mechanism optimization; off-chain scaling includes payment channel networks and Layer-2 Rollups. By comparing and analyzing the technical principles, advantages, limitations, and applicable scenarios of various solutions, this paper reveals that “on-chain basic optimization and off-chain collaborative scaling" has become the mainstream direction of blockchain scalability research. Building on this, Directed Acyclic Graphs (DAG) are highlighted in a separate section, detailing the technical principles and representative systems of three DAG solutions: natural structure, parallel structure, and main-chain structure. Finally, the paper looks forward to the future research trends of blockchain data structures and scaling technologies, providing a reference for theoretical research and engineering practice in related fields.