Re: Function that creates a custom (temporary) table AND returns a pointer to it = impossible in pg?

What I want is something similar to this:

CREATE OR REPLACE FUNCTION f( /* "some args..." */)
RETURNS text AS
$BODY$
DECLARE
...
BEGIN
DROP TABLE IF EXISTS tbl_temp;

CREATE TEMPORARY TABLE tbl_temp(
-- "based on args..."
);

WHILE
INSERT INTO tbl_temp VALUES (/*"some values"*/);
END LOOP;

/*create indexes on it, manipulate, whatever...*/

RETURN 'tbl_temp'::text;

END;
$BODY$
LANGUAGE 'plpgsql'

Basically, what I want is a similar function f() that returns me a "pointer"
to the table which I can use in some query like this: SELECT * FROM
regclass(f()); Currently, this query only gives me one row 'tbl_temp'...,
but not what I want: "SELECT * FROM tbl_temp;" Can this be done in Postgres?

Original post:
http://forums.devshed.com/postgresql-help-21/function-that-creates-a-custom-table-and-returns-a-pointer-675539.html

Kind regards,
Davor

The impossibility of a function as a pointer seems clear to me: if it was
possible, it would switch off the planner. But it should not be the case.
For example: the planner could postpone planning if it detected a function
that returns a set, execute it and wait for the results, and then use the
results for planning of the outer query. This would imply a layered query
planning/execution.

I think this approach would seriously extend the possibilities of pg in a
rather "object-oriented" way. Or am I wrong?

Regards,
Davor

"Davor J." <DavorJ(at)live(dot)com> wrote in message
news:hl1170$29jn$1(at)news(dot)hub(dot)org(dot)(dot)(dot)
> What I want is something similar to this:
>
> CREATE OR REPLACE FUNCTION f( /* "some args..." */)
> RETURNS text AS
> $BODY$
> DECLARE
> ...
> BEGIN
> DROP TABLE IF EXISTS tbl_temp;
>
> CREATE TEMPORARY TABLE tbl_temp(
> -- "based on args..."
> );
>
> WHILE
> INSERT INTO tbl_temp VALUES (/*"some values"*/);
> END LOOP;
>
> /*create indexes on it, manipulate, whatever...*/
>
> RETURN 'tbl_temp'::text;
>
> END;
> $BODY$
> LANGUAGE 'plpgsql'
>
> Basically, what I want is a similar function f() that returns me a
> "pointer" to the table which I can use in some query like this: SELECT *
> FROM regclass(f()); Currently, this query only gives me one row
> 'tbl_temp'..., but not what I want: "SELECT * FROM tbl_temp;" Can this be
> done in Postgres?
>
> Original post:
> http://forums.devshed.com/postgresql-help-21/function-that-creates-a-custom-table-and-returns-a-pointer-675539.html
>
> Kind regards,
> Davor
>

In response to Davor J. :
> What I want is something similar to this:
>
>
> Basically, what I want is a similar function f() that returns me a "pointer"
> to the table which I can use in some query like this: SELECT * FROM
> regclass(f()); Currently, this query only gives me one row 'tbl_temp'...,
> but not what I want: "SELECT * FROM tbl_temp;" Can this be done in Postgres?

Take a look at
http://okbob.blogspot.com/2008/08/using-cursors-for-generating-cross.html

--
Andreas Kretschmer
Kontakt: Heynitz: 035242/47150, D1: 0160/7141639 (mehr: -> Header)
GnuPG: 0x31720C99, 1006 CCB4 A326 1D42 6431 2EB0 389D 1DC2 3172 0C99

Thank you for the link Andreas. It was helpfull, but still not quite what I
need.

Regards,
Davor

""A. Kretschmer"" <andreas(dot)kretschmer(at)schollglas(dot)com> wrote in message
news:20100212114635(dot)GB25282(at)a-kretschmer(dot)de(dot)(dot)(dot)
> In response to Davor J. :
>> What I want is something similar to this:
>>
>>
>> Basically, what I want is a similar function f() that returns me a
>> "pointer"
>> to the table which I can use in some query like this: SELECT * FROM
>> regclass(f()); Currently, this query only gives me one row 'tbl_temp'...,
>> but not what I want: "SELECT * FROM tbl_temp;" Can this be done in
>> Postgres?
>
> Take a look at
> http://okbob.blogspot.com/2008/08/using-cursors-for-generating-cross.html
>
>
> --
> Andreas Kretschmer
> Kontakt: Heynitz: 035242/47150, D1: 0160/7141639 (mehr: -> Header)
> GnuPG: 0x31720C99, 1006 CCB4 A326 1D42 6431 2EB0 389D 1DC2 3172 0C99
>
> --
> Sent via pgsql-general mailing list (pgsql-general(at)postgresql(dot)org)
> To make changes to your subscription:
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>