Help with multithreading SQL

I am attempting to make a plugin that would need to synchronise data with an external MySQL database every x ticks. I would like to use multiple threads so to not slow the main thread but am unsure what is the 'best' way to do this.

I am not too great at explaining things so I have created an image on the techniques I have thought of using so far.


Are any of these the 'correct' way of doing things?

I recall hearing somewhere that you can send...

Help with multithreading SQL