Re: After 10 -> 15 upgrade getting "cannot commit while a portal is pinned" on one python function

Jeff Ross <jross@openvistas.net>

From: Jeff Ross <jross@openvistas.net>
To: pgsql-general@lists.postgresql.org
Date: 2024-03-27T23:05:21Z
Lists: pgsql-general
On 3/27/24 15:44, Tom Lane wrote:

> Perhaps "pinned" in the error message means "open"?
> No, it means "pinned" ... but I see that plpython pins the portal
> underlying any PLyCursor object it creates.  Most of our PLs do
> that too, to prevent a portal from disappearing under them (e.g.
> if you were to try to close the portal directly from SQL rather
> than via whatever mechanism the PL wants you to use).
>
>> I added a cursor.close() as the last line called in that function and it
>> works again.
> It looks to me like PLy_cursor_close does pretty much exactly the same
> cleanup as PLy_cursor_dealloc, including unpinning and closing the
> underlying portal.  I'm far from a Python expert, but I suspect that
> the docs you quote intend to say "cursors are disposed of when Python
> garbage-collects them", and that the reason your code is failing is
> that there's still a reference to the PLyCursor somewhere after the
> plpython function exits, perhaps in a Python global variable.
>
> 			regards, tom lane
>
>
Thank you for your reply, as always, Tom!

Debugging at this level might well be over my paygrade ;-)

I just happy that the function works again, and that I was able to share 
a solution to this apparently rare error with the community.

Jeff