C# correct alternative for SQL Numeric

Question

I've been playing around with Numerics and the c# 128-bit counterpart decimal and noticed some differences. For one, C# decimal is 128-bit, while SQL numeric occupies an extra byte.

What I was wondering is: what would be the 'correct' (fast) SQL compliant way to implement a Numeric/Decimal in C# (just as an 'academic question')?

Oh and to make the question a bit harder:

• Of course I want the data structure to occupy as little bytes as possible.
• Like the normal 'decimal' in C#, I want to be able to add, subtract, divide and multiply.

Because a numeric with 17 bytes is the hardest, this is the one that really interests me. The other precisions are just variations on it that probably require another struct.

Answer 1

System.Data.SqlTypes.SqlDecimal already offers this. It offers the arithmetic as well.