Primary key - VARBINARY or BLOB or VARCHAR for the primary key UUID

Question

I use UUID as primary key in one of the tables.
What are the pros and cons of having this field as varchar / varbinary / blob?

Answer 1

The difference between textual and binary UUIDs is a significant number of bytes - 16 for binary representation versus 30+ for text - so the binary path is the way to go. I would choose VARBINARY over BLOB - if only because VARBINARY is a newer type (and, based on the background of SQL Server, I know that VARBINARY can be stored in a string).