What method is used to manage concurrent access to data, where one transaction is denied access until another is complete?

Locking is a vital method used in database management systems to control concurrent access to data, ensuring data integrity and consistency. When multiple transactions are happening simultaneously, there is a risk that they may conflict with one another, leading to violations of data integrity. Locking addresses this by restricting data access for a transaction until it is completed.

When a transaction initiates, it can place a lock on specific data elements that it needs to access. While the lock is in place, other transactions attempting to access the same data can be prevented from doing so. This ensures that no other transaction can interfere until the first transaction has finished its operations and released the lock. This method is critical in environments where many users or processes may need to read or write the same data simultaneously, helping to avoid issues such as lost updates or dirty reads.

Understanding this method is crucial for anyone involved in database design and management, as it plays a significant role in ensuring that databases remain reliable and accurate under multiple user operations.