Re: Can not cancel a call to a function that has opened a refcursor - Mailing list pgsql-bugs

From Dave Cramer
Subject Re: Can not cancel a call to a function that has opened a refcursor
Date
Msg-id CADK3HH+1yN7x3CVgU+9JtCmWV0Ta0YXyYCQbDNUtdgVFVr-S0Q@mail.gmail.com
Whole thread Raw
In response to Re: Can not cancel a call to a function that has opened a refcursor  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-bugs


On Thu, 5 Aug 2021 at 11:19, Tom Lane <tgl@sss.pgh.pa.us> wrote:
Mike Knowsley <mike.knowsley@bidorbuy.co.za> writes:
> A request to cancel a call to a function does not cancel the function if the function has opened a refcursor which it is returning.

As far as I can see, there is no such bug; you're just misunderstanding
when the query referenced by the cursor will execute.  The function
test_delay_in_refcursor() sets up the cursor and returns basically
immediately (certainly in much less than 2 seconds), so the timeout
you have in the JDBC code will never fire.  The expected pg_sleep(5)
won't execute till you try to fetch something from the refcursor.

Trying this manually in psql, I get

...
CREATE FUNCTION
regression=# \timing
Timing is on.
regression=# begin;
BEGIN
Time: 0.306 ms
regression=*# select test_delay_in_refcursor();
 test_delay_in_refcursor
-------------------------
 <unnamed portal 1>
(1 row)

Time: 0.314 ms
regression=*# fetch from "<unnamed portal 1>";
 ?column? | pg_sleep
----------+----------
 test     |
(1 row)

Time: 5005.475 ms (00:05.005)

I could have canceled the FETCH (and doing so works);
but I'm way too old and slow to cancel the submillisecond
setup step.


Ya, that was the other idea I had.

Dave

pgsql-bugs by date:

Previous
From: "David G. Johnston"
Date:
Subject: Re: BUG #17134: pg_restore ERROR: operator does not exist: util.ltree = util.ltree
Next
From: vinay kumar
Date:
Subject: Re: BUG #17134: pg_restore ERROR: operator does not exist: util.ltree = util.ltree