On 12/22/2011 11:34 AM, Robert Haas wrote:
> On Thu, Dec 22, 2011 at 1:04 AM, Joey Adams<joeyadams3.14159@gmail.com> wrote:
>> What I'm wondering is: how complex would it be to add such a feature
>> to PostgreSQL's type system?
> Very.
>
> It's been discussed before, although I can't tell you the subject
> lines of the threads off the top of my head. The basic problem is
> that there is a ton of code that assumes that a type is fully
> identified by an OID, and all of that code would need to be changed.
And frankly I'd expect there to be serious resistance to such a change.
It's not just a question of how hard it would be, but how advisable.
We have an extremely rich and uniquely extensible type system, and we've
added a number of somewhat generic features over the years. I'd need a
lot of convincing that we need fully generic types (and I came from the
Ada world many years ago which was the inspiration for many such features).
cheers
andrew