What is the function of a Read Lock?

A Read Lock is designed to allow multiple transactions to read the same data simultaneously while preventing modifications to that data. This type of locking mechanism enables consistency and integrity in a database by ensuring that when a read operation is occurring, no concurrent write operations can modify the data being read.

By implementing a Read Lock, the system blocks Write and Exclusive locks on the same data item. This ensures that as long as there is an active Read Lock on a piece of data, no updates or deletions can be performed by other transactions. Therefore, the essence of a Read Lock is to maintain data integrity during read operations by preventing potentially conflicting write actions. When a transaction holds a Read Lock, it guarantees that the data being accessed remains unchanged until the lock is released.

This characteristic of Read Locks helps in supporting concurrent access to data for read operations while ensuring that the data remains stable and consistent, preventing modifications that could lead to inconsistencies during the read processes.