Connecting front end and back end side is difficult. The main problem is the protocol itself. It is stateless. Connection is being re-created each time. HTTP/2 changes this behavior a little bit, but this is the transport layer only. Multiple requests/responses can be handled in a different order. It means there are many traps waiting for a developer.
Month: January 2017
Distributed Transaction Coordination is sometimes slow, but guarantees the system consistency. You do not need to care about infrastructure things. I will describe a problem that appears when you have no DTC and you have two independent databases.
SQL query engine is prepared to return correct results as soon as possible. But correctness means being correct from mathematical perspective. Problem that I will describe is obvious, but it is not what you sometimes expect from SQL engine.