MYSQL OR vs IN performance

Question

I am wondering if there is any difference in regards to performance between the following

SELECT ... FROM ... WHERE someFIELD IN(1,2,3,4)

SELECT ... FROM ..         


        

Answer 1

I think one explanation to sunseeker's observation is MySQL actually sort the values in the IN statement if they are all static values and using binary search, which is more efficient than the plain OR alternative. I can't remember where I've read that, but sunseeker's result seems to be a proof.