Re: Why doesn't the SERIAL data type automatically have a UNIQUE

You're right, Tom. I'm sure someone has a use for a serial field that 
isn't unique. I just assumed that it was. I guess I didn't read the 
documentation closely enough. At any rate, I had a table using a serial 
field that I had to restore to a previous date when I noticed that I 
forgot to set the sequence to the most recent value... user continued 
adding data to this table and it started causing some problems. It just 
seems like most situations would want it unique... to ensure integrity. 
But I guess you need to choose constraint for built-in data types that 
follow more of a one-size-fits-all  philosophy.  And hey,  how hard can 
it be to add  the word UNIQUE when I'm creating tables?

Ferindo

Tom Lane wrote:
> Ferindo Middleton Jr <fmiddleton@verizon.net> writes:
>   
>> Is there some reason why the SERIAL data type doesn't automatically have 
>> a UNIQUE CONSTRAINT.
>>     
>
> It used to, and then we decoupled it.  I don't think "I have no use for
> one without the other" translates to an argument that no one has a use
> for it ...
>
>             regards, tom lane
>
>