Dear guys who developed parse, could you tell me how the data saving works there (using MongoDB). I’m planning to use the load balancer attached to the same Mongo. Maybe the questions are more related to the MongoDB, I’m not sure.
Let’s say we have 2 concurrent users editing the same record and they saved it at the same time.
Are updates merged - let’s say one user updated one of the columns and the second user updated the other column of the same record. Is there a chance that DB will save only one update?
If both updates will always be applied then I have the second question here:
Is there a chance that returned data from the save object calls of both concurrent users won’t return the final data after both updates?
Is the createdAt column determining the real order of the operations on the DB or there is a chance that data with a lower createdAt will appear in DB later than another record with higher createdAt.
Is there any way to use transactions when we use load balancer and multiple parse servers (few updated records at the same time)?