Is normalizing the gender table going too far?

Question

I am not a database guy, but am trying to clean up another database. So my question is would normalizing the gender table be going too far?

User table:
userid int pk,
genderid char(1) fk
etc...

gender table:
genderid char(1) pk,
gender varchar(20)

Now at first it seemed silly to me, but then I considered it because i can then have a constant data source to populate from or bind from. I will be using WPF. If it was another framework I would probably avoid it, but what do you think?

Answer 1

Whether or not you choose to normalize your table structure to accomodate gender is going to depend on the requirements of your application and your business requirements.

I would normalize if:

• You want to be able to manage the "description" of a gender in the database, and not in code.
  • This allows you to quickly change the description from Man/Woman to Male/Female, for example.
• Your application currently must handle, or will possible handle in the future, localization requirements, i.e. being able to specify gender in different languages.
• Your business requires that everything be normalized.

I would not normalize if:

• You have a relatively simple application where you can easily manage the description of the gender in code rather than in the database.
• You have tight programmatic control of the data going in and out of the gender field such that you can ensure consistency of the data in that field.
• You only care about the gender field for information capture, meaning, you don't have a lot of programmatic need to update this field once it is set the first time.

Answer 2

I'm also not a database guy but I do it. It gives me the possibility to assure that only the genders are entered, that are valid (referencial integrity) and I can also use it to populate the selection control.

Answer 3

I can think of applications where I'd use different columns for sex and gender, have three values for sex (male/female/decline to state) and six for gender (male/female/transgendered male/transgendered female/asexual/decline to state). Granted, I live in San Francisco, where there's an level of public discussion of transgender issues that much of the rest of the world is behind the curve on.

The point is: without a compelling reason to think otherwise, I'd assume that any simplifying assumption I made about demographics was limited and parochial. The cost of breaking sex out to its own table is small now and expensive later. I wouldn't avoid the small cost on the basis of an assumption.

Answer 4

Well, your company might have a requirement that, if possible, everything be normalized.

Also, depending on the business & data, you might need to include transgenders as well which would create 3+ genders (I don't know how many there are, haven't checked)