[Sergei]

Nothing can be done atcompeltly same time. You can't raise your hands at the same time, computer can't start two programs at the same time, MySQL server cannot respond to two requests at the same time. There is a difference, maybe it's 0.00000000000000000000000001ms, but don't say it's the same time.

And I don't know what can be messed up since I haven't seen someone using two connections for the same thing on the same database.