Deadlocks Consider the partial schedule Ta Ta lock-x (B) read (B) B=B-50 write (B) lock-s (A) read (A) lock-s (B) lock-x (A) Neither T3 nor T4 can make progress-executing lock-S(B) causes T4 to wait for T3 to release its lock on B,while executing lock-X(A)causes T3 to wait for T4 to release its lock on A. Such a situation is called a deadlock. To handle a deadlock one of T3 or T4 must be rolled back and its locks released. Database System Concepts-6th Edition 15.11 ©Silberschat乜，Korth and SudarshanDatabase System Concepts - 6 15.11 ©Silberschatz, Korth and Sudarshan th Edition Deadlocks Consider the partial schedule Neither T3 nor T4 can make progress — executing lock-S(B) causes T4 to wait for T3 to release its lock on B, while executing lock-X(A) causes T3 to wait for T4 to release its lock on A. Such a situation is called a deadlock. To handle a deadlock one of T3 or T4 must be rolled back and its locks released