Summary

In this chapter, we learned about textbook relational database theory on ACID in the context of MongoDB.

Then, we focused on multi-document ACID transactions and applied them in two use cases using Ruby and Python. We learned about when to use MongoDB transactions and when not to use them, how to use them, their best practices, and their limitations.

In the next chapter, we will deal with one of the most commonly-used features of MongoDB – aggregation.