Storing MD5 Hash in SQL Server

Question

In SQL Server would a varbinary(16) be the most efficient way of storing an MD5 hash? Won't be doing anything with it except returning it in a linq query.

Answer 1

Based on the documentation on MSDN and my experience, binary is better, since the md5 hash does not vary in size.

The size for a binary data type is n bytes, so the size of the data. The size of a varbinary data type is n bytes + 2 bytes on top of the size of the data.

Answer 2

Null values change things:

A null varbinary(16) is 2 bytes.
A null binary(16) is 16 bytes.
16 bytes stored in varbinary(16) takes 18 bytes.
16 bytes in binary(16) takes 16 bytes.

https://stackoverflow.com/a/3731195