Re: No serial type

On Nov 18, 2008, at 10:37 AM, Tom Lane wrote:

> "Scott Marlowe" <scott(dot)marlowe(at)gmail(dot)com> writes:
>> On Tue, Nov 18, 2008 at 10:24 AM, Simon Connah
>> <simon(dot)n(dot)connah(at)btopenworld(dot)com> wrote:
>>> But whenever I try and update my column to this type it says that
>>> it can not
>>> find that data type. Am I doing something wrong?
>
>> Serial is a "pseudotype".
>
> Perhaps better to say it's a macro, which is currently recognized by
> column creation but not ALTER COLUMN TYPE. In recent versions you
> could
> do "ALTER TABLE ADD COLUMN foo serial", if that helps.
>
> I'm not sure if it'd be sensible to allow "ALTER COLUMN TYPE serial";
> it seems like that might do more than you were expecting. ALTER TYPE
> is a pretty low-level operation, imo.

I agree, there would also be the question of the sequence's starting
value. Some people would "expect" it to find the max value already in
the column and automatically set it's start value based on that which
may in turn surprise others.

Erik Jones, Database Administrator
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