Is there a good reason I see VARCHAR(255) used so often (as opposed to another length)?

Question

In multiple courses, books, and jobs, I have seen text fields defined as VARCHAR(255) as kind of the default for \"shortish\" text. Is there any good reason that a length o

Answer 1

255 is used because it's the largest number of characters that can be counted with an 8-bit number. It maximizes the use of the 8-bit count, without frivolously requiring another whole byte to count the characters above 255.

When used this way, VarChar only uses the number of bytes + 1 to store your text, so you might as well set it to 255, unless you want a hard limit (like 50) on the number of characters in the field.