TINYINT vs Nullable BIT performance in MS SQL Server [closed]

We need three modes to display the status of users in the database!
We can do it in two ways

Nullable BIT:

Null: Not checked

0: Not accepted

1: accepted

TINYINT

0: Not checked

1: accepted

2: Not accepted

Which data type is better when we need to represent three values?

It’s highly unlikely that there is a material performance difference here.

So the choice is between

create table AppUser
(
  Id int identity primary key,
  Name nvarchar(200) not null,
  UserAccepted bit null
)

And

create table UserStatus
(
  Id tinyint primary key,
  Description varchar(200)
)

create table AppUser
(
  Id int identity primary key,
  Name nvarchar(200) not null,
  UserStatus tinyint not null references UserStatus default 0
)

And while one might be preferable in your particular application, they are both reasonable designs.

I would go with TINYINT for these reasons:

1. You might come up with other modes – for example, “verifying”
2. Bit can’t be aggregated – that usually comes up with PIVOT function, where you have to aggregate – you first need to cast to int family type.
3. Single bit column doesn’t actually provide storage savings – it still takes a byte (the first bit in a byte) – other columns would provide a storage saving