Concurrency Control Modify concurrency control schemes for use in distributed environment. We assume that each site participates in the execution of a commit protocol to ensure global transaction atomicity. We assume all replicas of any item are updated Will see how to relax this in case of site failures later Database System Concepts-7th Edition 23.23 ©Silberscha乜，Korth and SudarshanDatabase System Concepts - 7 23.23 ©Silberschatz, Korth and Sudarshan th Edition Concurrency Control ▪ Modify concurrency control schemes for use in distributed environment. ▪ We assume that each site participates in the execution of a commit protocol to ensure global transaction atomicity. ▪ We assume all replicas of any item are updated • Will see how to relax this in case of site failures later