Re: BUG #5043: Stored procedure returning different results for same arguments

The following bug has been logged online:

Bug reference: 5043
Logged by: Martin Edlman
Email address: edlman(at)fortech(dot)cz
PostgreSQL version: 8.2.0
Operating system: Linux (RHEL 4.4)
Description: Stored procedure returning different results for same
arguments
Details:

I have a stored procedure (SP) get_schemebind_date(int, date) which looks up
a date of validity of a payment scheme. Table schemebind contains valid_from
(date), schemeid (int), contractid (int).

There are these records in schemebind
'2008-11-01', 123, 1004
'2009-09-01', 456, 1004

When I call "select get_schemebind_date(1004,'2009-09-01')" from psql I get
correct result, which is 2009-09-01.
But when I call it from within another sp (let's call it xfunc(int, date,
varchar), I get wrong result 2008-11-01. The date passed to xfunc() is then
passed to get_schemebind_date().

I enabled RAISE NOTICE to see the parameters and the result, in case I call
get_schemebind_date() from console I see
NOTICE: get_schemebind_date(1004, 2009-09-01) = 2009-09-01
In case get_schemebind_date() is called from xfunc() I see
NOTICE: get_schemebind_date(1004, 2009-09-01) = 2008-11-01

I really don't understand it. All parameters are of type date, column
valid_from is of type date as well.

If you need full code of xfunc, I can send it to you.

CREATE OR REPLACE FUNCTION get_schemebind_date(integer, date)
RETURNS date AS
$BODY$
DECLARE
rec RECORD;
con ALIAS FOR $1;
dat ALIAS FOR $2;
BEGIN
SELECT max(valid_from) AS vf
INTO rec
FROM schemebind
WHERE valid_from <= dat AND contractid = con;
RAISE NOTICE 'get_schemebind_date(%, %) = %', con, dat, rec.vf;
IF FOUND THEN
RETURN rec.vf;
END IF;
RETURN NULL;
END
$BODY$
LANGUAGE 'plpgsql' VOLATILE;
ALTER FUNCTION get_schemebind_date(integer, date) OWNER TO postgres;

Hello

please send function xfunc. Your code looks well.

please try sql function

CREATE OR REPLACE FUNCTION get_schemebind_date(integer, date)
RETURNS date AS $$
SELECT max(valid_from)
FROM schemebind
WHERE valid_from <= $2 AND contractid = $1;
$$ LANGUAGE sql;

has it same behave like plpgsql function?

regards
Pavel Stehule

2009/9/8 Martin Edlman <edlman(at)fortech(dot)cz>:
>
> The following bug has been logged online:
>
> Bug reference:      5043
> Logged by:          Martin Edlman
> Email address:      edlman(at)fortech(dot)cz
> PostgreSQL version: 8.2.0
> Operating system:   Linux (RHEL 4.4)
> Description:        Stored procedure returning different results for same
> arguments
> Details:
>
> I have a stored procedure (SP) get_schemebind_date(int, date) which looks up
> a date of validity of a payment scheme. Table schemebind contains valid_from
> (date), schemeid (int), contractid (int).
>
> There are these records in schemebind
> '2008-11-01', 123, 1004
> '2009-09-01', 456, 1004
>
> When I call "select get_schemebind_date(1004,'2009-09-01')" from psql I get
> correct result, which is 2009-09-01.
> But when I call it from within another sp (let's call it xfunc(int, date,
> varchar), I get wrong result 2008-11-01. The date passed to xfunc() is then
> passed to get_schemebind_date().
>
> I enabled RAISE NOTICE to see the parameters and the result, in case I call
> get_schemebind_date() from console I see
> NOTICE: get_schemebind_date(1004, 2009-09-01) = 2009-09-01
> In case get_schemebind_date() is called from xfunc() I see
> NOTICE: get_schemebind_date(1004, 2009-09-01) = 2008-11-01
>
> I really don't understand it. All parameters are of type date, column
> valid_from is of type date as well.
>
> If you need full code of xfunc, I can send it to you.
>
> CREATE OR REPLACE FUNCTION get_schemebind_date(integer, date)
>  RETURNS date AS
> $BODY$
> DECLARE
>        rec RECORD;
>        con ALIAS FOR $1;
>        dat ALIAS FOR $2;
> BEGIN
>        SELECT max(valid_from) AS vf
>                INTO rec
>                FROM schemebind
>                WHERE valid_from <= dat AND contractid = con;
>        RAISE NOTICE 'get_schemebind_date(%, %) = %', con, dat, rec.vf;
>        IF FOUND THEN
>                RETURN rec.vf;
>        END IF;
>        RETURN NULL;
> END
> $BODY$
> LANGUAGE 'plpgsql' VOLATILE;
> ALTER FUNCTION get_schemebind_date(integer, date) OWNER TO postgres;
>
> --
> Sent via pgsql-bugs mailing list (pgsql-bugs(at)postgresql(dot)org)
> To make changes to your subscription:
> http://www.postgresql.org/mailpref/pgsql-bugs
>

"Martin Edlman" <edlman(at)fortech(dot)cz> writes:
> When I call "select get_schemebind_date(1004,'2009-09-01')" from psql I get
> correct result, which is 2009-09-01.
> But when I call it from within another sp (let's call it xfunc(int, date,
> varchar), I get wrong result 2008-11-01.

The only thought that comes to mind is that maybe you've got two
tables named schemebind in different schemas, and the other function
is changing the search_path?

However, 8.2.0 is exceedingly out of date and full of known bugs.
Really the first thing you ought to do is update to 8.2.latest.

regards, tom lane

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Hello,

> please send function xfunc. Your code looks well.
> please try sql function
> ...
> has it same behave like plpgsql function?

Yes, result is the same - it returns 2008-11-01

I made further investigation - it seems the problem is here between the
keyboard and the chair :-)

As I wrote an answer for you I realized the problem. The xfunc() and
therefore get_schemebind_date() is called from a trigger AFTER DELETE ON
schemebind. So the trigger deletes the '2009-09-01' record,
get_schemebind_date() then returns correct result '2008-11-01'. But
xfunc() then fails and the trigger operation is rolled back and I see
the '2009-09-01' record again...
Sorry guys for bothering you and taking your time.

Regards,
- --
Martin Edlman
Fortech, spol. s r.o,
Ropkova 51, 57001 Litomyšl
Public GPG key: http://edas.visaci.cz/#gpgkeys
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2009/9/9 Martin Edlman <edlman(at)fortech(dot)cz>:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> Hello,
>
>> please send function xfunc. Your code looks well.
>> please try sql function
>> ...
>> has it same behave like plpgsql function?
>
> Yes, result is the same - it returns 2008-11-01
>
> I made further investigation - it seems the problem is here between the
> keyboard and the chair :-)
>
> As I wrote an answer for you I realized the problem. The xfunc() and
> therefore get_schemebind_date() is called from a trigger AFTER DELETE ON
> schemebind. So the trigger deletes the '2009-09-01' record,
> get_schemebind_date() then returns correct result '2008-11-01'. But
> xfunc() then fails and the trigger operation is rolled back and I see
> the '2009-09-01' record again...
> Sorry guys for bothering you and taking your time.

v pohode :)

Pavel
>
> Regards,
> - --
> Martin Edlman
> Fortech, spol. s r.o,
> Ropkova 51, 57001 Litomyšl
> Public GPG key: http://edas.visaci.cz/#gpgkeys
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> Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org/
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> =ZVLv
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>