What does a Write Lock prevent?

A Write Lock is designed to prevent other transactions from accessing the data that it has locked, ensuring the integrity of operations that modify data. Specifically, a Write Lock blocks other transactions from obtaining Read Locks, which would allow them to read the data that is being modified, as well as other Write Locks or Exclusive Locks, preventing concurrent modifications that could lead to conflicting changes.

This capability is crucial in database management systems to maintain consistency and avoid issues like lost updates or dirty reads, where one transaction might see an incomplete view of the data being written by another transaction. The Write Lock mechanism ensures that areas of data being modified are exclusively held until the transaction is completed and released.

The other options, while they may engage with the concepts of locking, do not accurately reflect the comprehensive protection offered by a Write Lock. For instance, limiting locks to only Read or Access types doesn't encapsulate the broader functionality of preventing simultaneous Writes, which is essential for maintaining data integrity during updates.