What is a deadlock in a database system?
a) A situation where two or more transactions are waiting for each other to release resources
b) A state where all transactions are completed successfully
c) A technique to backup the database
d) A method of recovering from system failure
Answer:
a) A situation where two or more transactions are waiting for each other to release resources
Explanation:
A deadlock in a database system occurs when two or more transactions are waiting for each other to release resources, creating a cycle of dependency that prevents any of the transactions from proceeding. This can happen when multiple transactions lock the same resources in different orders.
Deadlock is a serious issue in multi-user environments and must be detected and resolved to prevent the database from stalling. Techniques to resolve deadlock include deadlock prevention, detection, and recovery, such as rolling back one of the involved transactions.
DBMSs often include mechanisms to detect and handle deadlocks automatically to ensure smooth transaction processing.