In what cases is it necessary to use atomic operations or transactions?

The mechanism of atomic operations or transactions is necessary when it is required to ensure the integrity and consistency of data when performing multiple related operations. This is especially important if operations can be interrupted or executed in parallel, for example, when working with databases or multi-threaded access to shared resources.

Examples of cases:

• Updating multiple related records in a database, where all changes must be applied together or not at all.
• Ensuring correctness during concurrent access to shared data in a multi-threaded application.
• Executing a sequence of operations where an error at any step requires rolling back all previous changes.

Transactions guarantee the properties of ACID (Atomicity, Consistency, Isolation, Durability), which prevents partial updates and race conditions.