MySQL Performance Questions

[random1]

Hey All,

 

I recently watched a talk about MySQL performance tips and would like to check a few points brought up about columns:

 

• BIGINT(50) should be changed to INT UNSIGNED
  
• Always assign columns as UNSIGNED unless there is a reason otherwise
  
• Always use NOT NULL unless there is a reason not to
  
• VARCHAR(255) is bad design and a defined data type is much better
  

 

Do these points seem right and reasonable?