database question

Why is concurrency important? What are binary locks and why are they generally not used? How does locking and unlocking operate? What is the difference between implicit and explicit locks? What is meant by granularity and how does it relate to lock escalation? How do shared locks work? Explain the two-phase locking protocol What are the advantages and disadvantages of conservative and strict two-phase locking? How does timestamp ordering work? What is optimistic concurrency control? . What is deadlock and why is it undesirable? . Name multiple deadlock prevention techniques using and not using timestamps How does a wait-for graph work? Why is it more practical to detect rather than prevent deadlocks