Varchar(max) column not allowed to be a Primary Key in SQL Server

Question

Varchar(max) column not allowed to be a Primary Key in SQL Server.

What is the max length of a varchar type that can be made a primary key.

This might be a b

Answer 1

This question has already been answered in this thread; the short answer is that an index field cannot exceed 900 bytes. That said, it's generally a bad idea to use a long VARCHAR field as an index for myriad reasons such as efficiency and maintainability.

Answer 2

900 bytes is the max length for a primary key, this is a bad idea in my opinion, why don't you use a surrogate key instead?

Answer 3

The primary key is used in all other indexes to identify rows. Having a potentially multi-megabyte value as a key makes very little sense, hence the limit in general on total bytes in any key.