Final answer:
Multiple granularity locking (MGL) is a technique in database management systems for managing concurrency and consistency by allowing transactions to lock objects at multiple levels of granularity.
Step-by-step explanation:
Multiple granularity locking (MGL) is a locking mechanism used in database management systems to control concurrency and maintain consistency of transactions. MGL allows a transaction to lock objects at different granularity, such as at the database, table, page, or row level, providing the flexibility to have various levels of locks according to the needs of the transaction. This system enhances performance by allowing for more considerable concurrency, minimizing the number of lock and unlock operations, and reducing the potential for deadlocks as transactions do not need to request as many locks.
Considering the options provided, the answer to the student's question, "What is the meaning of Multiple granularity locking (MGL)?", is: 1) A locking mechanism used in database management systems.