有没有人有充分的证据证明 CHAR 比 VARCHAR 快?

Any benchmark, graph anything at all ? Its all academic and theoretical across the web.

Ok its not the first time that this question has been asked, they all say that using CHAR results in faster selects? I even read in MySQL books, its all the same but I have not come across any benchmark that proves this.

Can any one shed some light over this?

解决方案

This is simple logic, to simplify I'll take the example of a CSV file...

would it be faster to search in this line

1231;231;32345;21312;23435552;1231;1;243;211;3525321;44343112;

or this one

12;23;43;54;56;76;54;83;45;91;28;92

as long as you define your length correctly CHAR should be faster as the predefined format help the processing time.