Thread: BUG #5500: SPI_execute_plan_with_paramlist SPI_ERROR_TRANSACTION with savepoint

The following bug has been logged online:

Bug reference:      5500
Logged by:          Robert Walker
Email address:      robwalker01@speedymail.org
PostgreSQL version: 9.0 beta 2
Operating system:   Windows XP 32-bit SP2
Description:        SPI_execute_plan_with_paramlist SPI_ERROR_TRANSACTION
with savepoint
Details:

SPI_execute_plan_with_paramlist seems to be newly introduced into 9.0 beta
that is causing an error in pl/pgsql when attempting to create a savepoint.
This did not happen when using version 8.4 (which I assume was not using
SPI_execute_plan_with_paramlist), so I believe this is a regression.

The specific format of the error is:

ERROR: SPI_execute_plan_with_paramlist failed executing query "SAVEPOINT
savepoint_name": SPI_ERROR_TRANSACTION
SQL state: XX000
Context: PL/pgSQL function "add_foo" line 241 at SQL statement


Before the savepoint is only a couple of statements: one insert statement
and another insert statement using "returning *" into a variable. The
function parameters use %TYPE in order to help ensure the parameters match
the same type as the table column it is meant to deal with. The function's
return value is a rowtype of the results from the insert/returning right
before the savepoint.

If I comment out the few lines regarding savepoints, the function works (but
without error trapping of course), so I know it's not a syntax error or some
other type of error. PostgreSQL for some reason wants to use
SPI_execute_plan_with_paramlist and this causes the error.

"Robert Walker" <robwalker01@speedymail.org> writes:
> SPI_execute_plan_with_paramlist seems to be newly introduced into 9.0 beta
> that is causing an error in pl/pgsql when attempting to create a savepoint.
> This did not happen when using version 8.4 (which I assume was not using
> SPI_execute_plan_with_paramlist), so I believe this is a regression.

Um, it's never been the case that you could execute a SAVEPOINT
statement inside plpgsql.  I'd be interested to see the case that
you claim worked in 8.4.

            regards, tom lane

Excerpts from Robert Walker's message of vie jun 11 14:49:03 -0400 2010:

> SPI_execute_plan_with_paramlist seems to be newly introduced into 9.0 beta
> that is causing an error in pl/pgsql when attempting to create a savepoint.
> This did not happen when using version 8.4 (which I assume was not using
> SPI_execute_plan_with_paramlist), so I believe this is a regression.
>
> The specific format of the error is:
>
> ERROR: SPI_execute_plan_with_paramlist failed executing query "SAVEPOINT
> savepoint_name": SPI_ERROR_TRANSACTION

If it fails to fail on 8.4, that's a bug -- it is *supposed* not to
work.  If you want to use savepoints in plpgsql you need to use
EXCEPTION blocks.  Can you provide a working example in 8.4?

--
Álvaro Herrera <alvherre@commandprompt.com>
The PostgreSQL Company - Command Prompt, Inc.
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