What length should be given to a varchar column for maximum performance?

Question

MySQL

What to set the length of a column of type varchar 254 or 255?
mysql database innodb table view

Answer 1

Reading the documentation - dev.mysql.com/doc/refman/5.7/en/storage-requiremen...
VARCHAR(M), VARBINARY(M) - L + 1 bytes if column values ​​require 0 − 255 bytes, L + 2 bytes if values ​​may require more than 255 bytes
But imho it will still be slow with such a large varchar and even a key..

Answer 2

Ask as much as you really need, no need to overcap. Will work quickly if to hang up an index (it is checked up).

Answer 3

What are you going to store there? In principle, a simple char, if the length of the field is known in advance, will be better.

Answer 4

For example, Yii2 creates varchar(255) in migrations by default