Обсуждение: Improving ALTER TYPE support

I've been working on a function which returns a setof a composite type. Everytime I've changed the structure of the
returningsetof, I've had to change the type accordingly, which current means doing a drop type ... cascade down to the
function.We should allow one of the following: <br /><br />1) Add a REPLACE on CREATE TYPE (create or replace type)<br
/><br/>2) Allow ALTER TYPE to alter the definition of the type (currently it only allows changes to schema and
ownership)<br/><br />It may get tricky with the first option because there'd be orphaned dependencies on objects which
referencethat particular type while it's being re-created. <br /><br />I'll work on a patch according to feedback.  

John,

> I've been working on a function which returns a setof a composite type.
> Everytime I've changed the structure of the returning setof, I've had to
> change the type accordingly, which current means doing a drop type ...
> cascade down to the function. We should allow one of the following:

Why not go all the way and work out a way to define an SRF return type as a 
part of the function?  e.g.

CREATE OR REPLACE FUNCTION some_srf ( param1 int, param2 text )
RETURNS some_srf ( col1 int, col2 numeric ) AS ....

Then the "replace" function would automatically rebuild the type.

-- 
Josh Berkus
PostgreSQL @ Sun
San Francisco

Josh Berkus <josh@agliodbs.com> writes:
>> I've been working on a function which returns a setof a composite type.
>> Everytime I've changed the structure of the returning setof, I've had to
>> change the type accordingly, which current means doing a drop type ...
>> cascade down to the function. We should allow one of the following:

> Why not go all the way and work out a way to define an SRF return type as a 
> part of the function?  e.g.

Um, isn't that exactly what the OUT parameter support already gives you,
ie, an anonymous record type?
        regards, tom lane

"John Jawed" <johnjawed@gmail.com> writes:
> I guess I don't understand what one has to do with the other (SRF's
> returning records and OUT parameters). I always thought they were exclusive,
> could you elaborate?

(BTW, please don't post uselessly HTML-ified mail.)

If you write something like
create function foo (in p1 int, out r1 int, out r2 text)returns setof record

then you've effectively got a function returning an anonymous composite
type (here, with one int and one text column).  I don't see a case for
inventing a separate facility that will pretty much just duplicate this
functionality.
        regards, tom lane

Tom,

> If you write something like
>
>         create function foo (in p1 int, out r1 int, out r2 text)
>         returns setof record

D'oh!  I feel like a dork now.  I forgot we had this.

--
--Josh

Josh Berkus
PostgreSQL @ Sun
San Francisco

Ok, this way works and the proposed way isn't necessary.

On 5/24/06, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> "John Jawed" <johnjawed@gmail.com> writes:
> > I guess I don't understand what one has to do with the other (SRF's
> > returning records and OUT parameters). I always thought they were exclusive,
> > could you elaborate?
>
> (BTW, please don't post uselessly HTML-ified mail.)
>
> If you write something like
>
>         create function foo (in p1 int, out r1 int, out r2 text)
>         returns setof record
>
> then you've effectively got a function returning an anonymous composite
> type (here, with one int and one text column).  I don't see a case for
> inventing a separate facility that will pretty much just duplicate this
> functionality.
>
>                         regards, tom lane
>