Обсуждение: Refcursor problem

Hi,

I am running 7.2b3 and trying to make something like this work (new
refcursor stuff):

CREATE TABLE t (c text);

CREATE FUNCTION errtest(refcursor, text) RETURNS refcursor AS '
BEGIN
        OPEN $1 FOR SELECT c FROM t WHERE c=$2;
        RETURN $1;
END;
' LANGUAGE 'plpgsql';

INSERT INTO t VALUES ('123');

BEGIN;
SELECT errtest('rs', '123');
FETCH ALL IN rs;
COMMIT;

I am getting this error after FETCH ALL....

psql:errtest.sql:15: ERROR:  MemoryContextAlloc: invalid request size
2139062147

If I tweak the function, the size in the error message (2139062147) stays
the same.
However, if I change the function to

CREATE FUNCTION errtest(refcursor, integer) RETURNS refcursor AS '
BEGIN
        OPEN $1 FOR SELECT c FROM t WHERE c=text($2);
        RETURN $1;
END;
' LANGUAGE 'plpgsql';


BEGIN;
SELECT errtest('rs', 123);
FETCH ALL IN rs;
COMMIT;

everything works fine. Am I missing something here? Workaround?
The OS is Linux Red Hat 7.1, kernel 2.4.5, glibc 2.2.4

Thanks for your help!

Dmitry Fomichev

Dmitry Fomichev <dfomichev@reldata.com> writes:
> I am running 7.2b3 and trying to make something like this work (new
> refcursor stuff):

> CREATE TABLE t (c text);

> CREATE FUNCTION errtest(refcursor, text) RETURNS refcursor AS '
> BEGIN
>         OPEN $1 FOR SELECT c FROM t WHERE c=$2;
>         RETURN $1;
> END;
> ' LANGUAGE 'plpgsql';

> INSERT INTO t VALUES ('123');

> BEGIN;
> SELECT errtest('rs', '123');
> FETCH ALL IN rs;
> COMMIT;

> I am getting this error after FETCH ALL....

> psql:errtest.sql:15: ERROR:  MemoryContextAlloc: invalid request size
> 2139062147

Nasty.  It looks like SPI_cursor_open needs to be careful to copy
by-reference parameter values into the memory context created for
the cursor portal.  Will fix.

            regards, tom lane

Tom Lane wrote:
> Dmitry Fomichev <dfomichev@reldata.com> writes:
> > I am running 7.2b3 and trying to make something like this work (new
> > refcursor stuff):
>
> > CREATE TABLE t (c text);
>
> > CREATE FUNCTION errtest(refcursor, text) RETURNS refcursor AS '
> > BEGIN
> >         OPEN $1 FOR SELECT c FROM t WHERE c=$2;
> >         RETURN $1;
> > END;
> > ' LANGUAGE 'plpgsql';
>
> > INSERT INTO t VALUES ('123');
>
> > BEGIN;
> > SELECT errtest('rs', '123');
> > FETCH ALL IN rs;
> > COMMIT;
>
> > I am getting this error after FETCH ALL....
>
> > psql:errtest.sql:15: ERROR:  MemoryContextAlloc: invalid request size
> > 2139062147
>
> Nasty.  It looks like SPI_cursor_open needs to be careful to copy
> by-reference parameter values into the memory context created for
> the cursor portal.  Will fix.

    It doesn't do? Blame it on me. Thanks.


Jan

--

#======================================================================#
# It's easier to get forgiveness for being wrong than for being right. #
# Let's break this rule - forgive me.                                  #
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