Transaction support in MongoDB

Question

I am new to MongoDB. I read that MongoDB does not support multi-document transactionshere http://docs.mongodb.org/manual/faq/fundamentals/.

If I want to save data in two collections(A and B) atomically, then i can't do that using MongoDB i.e. if save fails in case of B, still A will have the data. Isn't it a big disadvantage?

Still, people are using MongoDB rather than RDBMS. Why?

Answer 1

MongoDB 4.0 adds support for multi-document ACID transactions now. For reference See Refrence

Answer 2

UPDATE MongoDB have already started to support multi-document transactions. https://docs.mongodb.com/manual/core/transactions/

MongoDB does not support multi-document transactions.

However, MongoDB does provide atomic operations on a single document. Often these document-level atomic operations are sufficient to solve problems that would require ACID transactions in a relational database.

For example, in MongoDB, you can embed related data in nested arrays or nested documents within a single document and update the entire document in a single atomic operation. Relational databases might represent the same kind of data with multiple tables and rows, which would require transaction support to update the data atomically.

Answer 3

MongoDB doesn't support transactions, but saving one document is atomic.

So, it is better to design you database schema in such a way, that all the data needed to be saved atomically will be placed in one document.