Distributed Transactions ■Local transactions Access/update data at only one database Global transactions Access/update data at more than one database Key issue:how to ensure ACID properties for transactions in a system with global transactions spanning multiple database Database System Concepts-7th Edition 23.2 ©Silberscha乜，Korth and SudarshanDatabase System Concepts - 7 23.2 ©Silberschatz, Korth and Sudarshan th Edition Distributed Transactions ▪ Local transactions • Access/update data at only one database ▪ Global transactions • Access/update data at more than one database ▪ Key issue: how to ensure ACID properties for transactions in a system with global transactions spanning multiple database