The paper "Untangling Blockchain: A Data Processing View of Blockchain Systems" by Tien Tuan Anh Dinh, Rui Liu, Meihui Zhang, Gang Chen, Beng Chin Ooi, and Ji Wang provides an in-depth survey of blockchain technologies, focusing on private blockchains. The authors analyze four key dimensions—distributed ledger, cryptography, consensus protocol, and smart contracts—to categorize and evaluate existing systems. They introduce BLOCKBENCH, a benchmarking framework designed to understand the performance of private blockchains against data processing workloads. Through comprehensive evaluations of Ethereum, Parity, and Hyperledger Fabric, the paper highlights performance gaps between blockchain and database systems and discusses trade-offs in the design space. The authors draw insights from database systems to propose research directions for improving blockchain performance, emphasizing the importance of design principles from databases to enhance blockchain capabilities. The paper concludes with a discussion on the state of the art in blockchain systems, their applications, and future research directions.The paper "Untangling Blockchain: A Data Processing View of Blockchain Systems" by Tien Tuan Anh Dinh, Rui Liu, Meihui Zhang, Gang Chen, Beng Chin Ooi, and Ji Wang provides an in-depth survey of blockchain technologies, focusing on private blockchains. The authors analyze four key dimensions—distributed ledger, cryptography, consensus protocol, and smart contracts—to categorize and evaluate existing systems. They introduce BLOCKBENCH, a benchmarking framework designed to understand the performance of private blockchains against data processing workloads. Through comprehensive evaluations of Ethereum, Parity, and Hyperledger Fabric, the paper highlights performance gaps between blockchain and database systems and discusses trade-offs in the design space. The authors draw insights from database systems to propose research directions for improving blockchain performance, emphasizing the importance of design principles from databases to enhance blockchain capabilities. The paper concludes with a discussion on the state of the art in blockchain systems, their applications, and future research directions.