Is there any reason for numeric rather than int in T-SQL?

Question

Why would someone use numeric(12, 0) datatype for a simple integer ID column? If you have a reason why this is better than int or bigint I would like to hear it.

We are not doing any math on this column, it is simply an ID used for foreign key linking.

I am compiling a list of programming errors and performance issues about a product, and I want to be sure they didn't do this for some logical reason. If you follow this link: http://msdn.microsoft.com/en-us/library/ms187746.aspx

... you can see that the numeric(12, 0) uses 9 bytes of storage and being limited to 12 digits, theres a total of 2 trillion numbers if you include negatives. WHY would a person use this when they could use a bigint and get 10 million times as many numbers with one byte less storage. Furthermore, since this is being used as a product ID, the 4 billion numbers of a standard int would have been more than enough.

So before I grab the torches and pitch forks - tell me what they are going to say in their defense?

And no, I'm not making a huge deal out of nothing, there are hundreds of issues like this in the software, and it's all causing a huge performance problem and using too much space in the database. And we paid over a million bucks for this crap... so I take it kinda seriously.

Answer 1

Perhaps they're used to working with Oracle?

All numeric types including ints are normalized to a standard single representation among all platforms.

Answer 2

There are many reasons to use numeric - for example - financial data and other stuffs which need to be accurate to certain decimal places. However for the example you cited above, a simple int would have done.

Perhaps sloppy programmers working who didn't know how to to design a database ?