Differences between “IS NULL” and “ISNULL()” in Mysql

Question

Is there any difference in performance between the operator IS NULL and the function ISNULL()?

Answer 1

Looking into the MySQL manual, they seem to be synonyms really.

• MySQL manual on IS NULL

• MySQL manual on ISNULL()

and even if they aren't, I would tend to trust the query optimizer to pick the best solution.