remove autoincrement for a keyfield

Yes, you need to use phpMyAdmin or similar software in order to do that.

thank you, another question: If I want to insert a custom auto-Increment logic for that field, what is the best event for that, Before record Added or Custom ADD?
what is you advice?

I think that BeforeAdd is an easier option in this case.

I've found that Before record Added bypass autoincrement for keyfield, so I'm able to insert custom autoincrement code without remove attribute.
Thank you!