mongodb atomic operations

MongoDB provides support for atomic operations on individual documents, allowing you to perform multiple operations as a single atomic transaction. Atomic operations are operations that are guaranteed to succeed or fail as a single unit of work, ensuring that the data remains consistent.

In MongoDB, there are several atomic operations that can be performed on individual documents. These include:

1. findAndModify(): This operation finds a document that matches a query and modifies it in a single atomic transaction. This operation can be used to perform updates, deletes, and inserts.

2. $addToSet: This operator adds an element to an array only if it doesn't already exist. If the element already exists, no change is made.

3. $push: This operator appends an element to an array. This operation is atomic when appending a single element.

4. $pull: This operator removes an element from an array. This operation is atomic when removing a single element.

5. $inc: This operator increments a numeric field by a specified value. This operation is atomic.

6. $set: This operator sets the value of a field in a document. This operation is atomic.

These atomic operations ensure that the data remains consistent, even in a high-concurrency environment. Atomic operations are especially useful in scenarios where multiple clients may be modifying the same data simultaneously.

It's important to note that not all operations in MongoDB are atomic. For example, a multi-document update or delete operation is not atomic, as it may affect multiple documents simultaneously. However, you can use the bulkWrite() method to group multiple update or delete operations into a single atomic transaction.