Re: what are the ways to avoid --- "ERROR: EXECUTE of SELECT ... INTO is not implemented yet" - Mailing list pgsql-bugs

From Shantanu
Subject Re: what are the ways to avoid --- "ERROR: EXECUTE of SELECT ... INTO is not implemented yet"
Date
Msg-id 97d558890805311021h29549564p8c67bba0ab853731@mail.gmail.com
Whole thread Raw
In response to Re: what are the ways to avoid --- "ERROR: EXECUTE of SELECT ... INTO is not implemented yet"  (tomas@tuxteam.de)
Responses Re: what are the ways to avoid --- "ERROR: EXECUTE of SELECT ... INTO is not implemented yet"  (tomas@tuxteam.de)
List pgsql-bugs
Here is my real use case

1) We have nornal SELECT ...INTO calls in the procedure calls
2) However we landed ourselves with the following problem
http://www.postgresql.org/docs/faqs.FAQ.html#item4.19

<snip>
4.19) Why do I get "relation with OID ##### does not exist" errors when
accessing temporary tables in PL/PgSQL functions?

In PostgreSQL versions < 8.3, PL/PgSQL caches function scripts, and an
unfortunate side effect is that if a PL/PgSQL function accesses a temporary
table, and that table is later dropped and recreated, and the function
called again, the function will fail because the cached function contents
still point to the old temporary table. The solution is to use EXECUTE for
temporary table access in PL/PgSQL. This will cause the query to be reparsed
every time.

This problem does not occur in PostgreSQL 8.3 and later.
</snip>

3) So the solution we are trying to implement is the EXECUTE command one.

This is causing the SELECT ...INTO problem


Upgrade is not an option :(

Currently the only available solution is
Use a temporary table where we write the local variable and make it read
from the table .

Any alternatives ?

~
Shantanu


On Sat, May 31, 2008 at 8:38 AM, <tomas@tuxteam.de> wrote:

> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> On Fri, May 30, 2008 at 09:57:49PM +0530, Shantanu wrote:
> > Hello experts,
> >
> >
> > I am facing this error.
> >
> > mydb=3D> select version();
> >                                             version
> >
> >
> -------------------------------------------------------------------------=
-------
> >
> >  PostgreSQL 8.1.9
> >
> > (1 row)
> >
> > mydb=3D> \i /tmp/test.sql
> > CREATE FUNCTION
> > mydb=3D> select sp_test();
> > ERROR:  EXECUTE of SELECT ... INTO is not implemented yet
> > CONTEXT:  PL/pgSQL function "sp_test" line 4 at execute statement
> >
> >
> > mydb=3D>
> > [1]+  Stopped                 su - dbu
> > mymachine<root># cat /tmp/test.sql
> > create or replace function sp_test() RETURNS void as $$
> > declare
> >         l_var timestamp;
> > begin
> > execute 'SELECT NOW() INTO l_var';
>   ^^^^^^^^^^^^^^^^^^
>
> Why do you need execute '...' at all?  Why not directly do instead
>
>  SELECT NOW() into l_var;
>
> What is your "real" use case?
>
> Note that if you really need the dynamic command, you might put its
> result int a variable, like so:
>
>  EXECUTE 'SELECT NOW()' INTO l_var;
>
> ...but if we don't know what you are trying to achieve, it's difficult
> to provide meaningful recommendations.
>
> Regards
> - -- tom=E1s
> -----BEGIN PGP SIGNATURE-----
> Version: GnuPG v1.4.6 (GNU/Linux)
>
> iD8DBQFIQMEjBcgs9XrR2kYRAnaWAJ9Mpu/qvqzi911yiftbe3lLYZiyLgCfcWIl
> TKs78mgZiKFRZcHnmHMQnOw=3D
> =3DI2iD
> -----END PGP SIGNATURE-----
>

pgsql-bugs by date:

Previous
From: Tom Lane
Date:
Subject: Re: BUG #4216: Index scan goes wrong with crosstype comparison and between in one statement
Next
From: Shantanu
Date:
Subject: Re: what are the ways to avoid --- "ERROR: EXECUTE of SELECT ... INTO is not implemented yet"