Re: BUG #19473: regression error in dblink: another command is already in progress

On Sat, 9 May 2026 at 00:43, PG Bug reporting form
<noreply@postgresql.org> wrote:
>
> The following bug has been logged on the website:
>
> Bug reference:      19473
> Logged by:          Oleg Ivanov
> Email address:      o15611@gmail.com
> PostgreSQL version: 18.3
> Operating system:   Linux
> Description:
>
> Testcase:
> SELECT * FROM dblink('dbname=postgres user=postgres', $$ select 7; $$ ) as
> (col1 int);
> SELECT * FROM dblink_connect('connection1', 'host=/var/run/postgresql
> port=5432');
> SELECT * FROM dblink_send_query('connection1', $$ select 8 from pg_sleep(1);
> $$ );
> SELECT dblink_is_busy('connection1');
> SELECT * FROM dblink_get_result('connection1') as t(col1 int);
> --- SELECT dblink_is_busy('connection1');
> SELECT * FROM dblink_exec('connection1', $$ CHECKPOINT; $$);
> SELECT * FROM dblink_disconnect('connection1');
>
>  col1
> ------
>     7
> (1 row)
>
>  dblink_connect
> ----------------
>  OK
> (1 row)
>
>  dblink_send_query
> -------------------
>                  1
> (1 row)
>
>  dblink_is_busy
> ----------------
>               1
> (1 row)
>
>  col1
> ------
>     8
> (1 row)
>
> ERROR:  another command is already in progress
> CONTEXT:  while executing command on dblink connection named "connection1"
>  dblink_disconnect
> -------------------
>  OK
> (1 row)
>
> There was no error in 16 version. The error appeared in 17 version. It
> seems, there is a regression bug.
> The workaround is to uncomment a commented statement.
>
>
>
>

Hi! Thank you for this report, I was able to reproduce this behaviour.
My git bisect shows that first commit where this errors out is d3c5f37

```
commit d3c5f37dd543498cc7c678815d3921823beec9e9 (HEAD)
Author: Noah Misch <noah@leadboat.com>
Date:   Mon Jan 8 11:39:56 2024 -0800

    Make dblink interruptible, via new libpqsrv APIs.

```


-- 
Best regards,
Kirill Reshke