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* Listen and notify in psql process
@ 2021-06-17 11:01 Sakshi Jain <sakshijain10388@gmail.com>
2021-06-17 11:04 ` Fwd: Listen and notify in psql process Sakshi Jain <sakshijain10388@gmail.com>
2021-06-17 14:22 ` Re: Listen and notify in psql process Erik Brandsberg <erik@heimdalldata.com>
0 siblings, 2 replies; 5+ messages in thread
From: Sakshi Jain @ 2021-06-17 11:01 UTC (permalink / raw)
To: pgsql-sql@lists.postgresql.org
Hi Team,
How to listen from within a psql process and get the payloads?
Do Postgres have any such a mechanism where in a session a process send a
"listen <name>" sql command and then gets a message if someone in the other
session issued a "notify <name>".
Please provide an example of how to do this.
--
*Thanks & Regards*
Sakshi Jain
New Delhi
8882433263
^ permalink raw reply [nested|flat] 5+ messages in thread
* Fwd: Listen and notify in psql process
2021-06-17 11:01 Listen and notify in psql process Sakshi Jain <sakshijain10388@gmail.com>
@ 2021-06-17 11:04 ` Sakshi Jain <sakshijain10388@gmail.com>
2021-06-17 11:45 ` Re: Listen and notify in psql process Ravi Krishna <srkrishna@yahoo.com>
2021-06-17 13:34 ` Re: Listen and notify in psql process Torsten Förtsch <tfoertsch123@gmail.com>
1 sibling, 2 replies; 5+ messages in thread
From: Sakshi Jain @ 2021-06-17 11:04 UTC (permalink / raw)
To: pgsql-general@lists.postgresql.org
Hi Team,
How to listen from within a psql process and get the payloads?
Do Postgresql have any such a mechanism where in a session a process send a
"listen <name>" sql command and then gets a message if someone in the other
session issued a "notify <name>".
Please provide an example of how to do this.
I am looking for listen to return some thing when a notify has been issued.
--
*Thanks & Regards*
Sakshi Jain
New Delhi
8882433263
--
*Thanks & Regards*
Sakshi Jain
New Delhi
8882433263
^ permalink raw reply [nested|flat] 5+ messages in thread
* Re: Listen and notify in psql process
2021-06-17 11:01 Listen and notify in psql process Sakshi Jain <sakshijain10388@gmail.com>
2021-06-17 11:04 ` Fwd: Listen and notify in psql process Sakshi Jain <sakshijain10388@gmail.com>
@ 2021-06-17 11:45 ` Ravi Krishna <srkrishna@yahoo.com>
1 sibling, 0 replies; 5+ messages in thread
From: Ravi Krishna @ 2021-06-17 11:45 UTC (permalink / raw)
To: pgsql-general@lists.postgresql.org <pgsql-general@lists.postgresql.org>; Sakshi Jain <sakshijain10388@gmail.com>
https://www.postgresql.org/docs/current/sql-notify.html
https://www.postgresql.org/docs/13/sql-listen.html
^ permalink raw reply [nested|flat] 5+ messages in thread
* Re: Listen and notify in psql process
2021-06-17 11:01 Listen and notify in psql process Sakshi Jain <sakshijain10388@gmail.com>
2021-06-17 11:04 ` Fwd: Listen and notify in psql process Sakshi Jain <sakshijain10388@gmail.com>
@ 2021-06-17 13:34 ` Torsten Förtsch <tfoertsch123@gmail.com>
1 sibling, 0 replies; 5+ messages in thread
From: Torsten Förtsch @ 2021-06-17 13:34 UTC (permalink / raw)
To: Sakshi Jain <sakshijain10388@gmail.com>; +Cc: pgsql-general <pgsql-general@lists.postgresql.org>
On Thu, Jun 17, 2021 at 1:04 PM Sakshi Jain <sakshijain10388@gmail.com>
wrote:
How to listen from within a psql process and get the payloads?
>
> Do Postgresql have any such a mechanism where in a session a process send
> a "listen <name>" sql command and then gets a message if someone in the
> other session issued a "notify <name>".
>
> Please provide an example of how to do this.
>
> I am looking for listen to return some thing when a notify has been issued.
>
Here is an example in perl. Basically you issue the LISTEN command. Then
you sit and watch the file descriptor to become ready. You do that outside
of a transaction. Once the descriptor is ready you call your driver's
version of notification read function until it comes back empty. That is
when you go back and wait for the next arrival.
$dbh->do("LISTEN channel");
my $sel = IO::Select->new;
$sel->add($dbh->{pg_socket});
while ($sel->can_read) {
while (my $notify = $dbh->pg_notifies) {
my ($name, $pid, $payload) = @$notify;
do_something($payload);
}
}
>
^ permalink raw reply [nested|flat] 5+ messages in thread
* Re: Listen and notify in psql process
2021-06-17 11:01 Listen and notify in psql process Sakshi Jain <sakshijain10388@gmail.com>
@ 2021-06-17 14:22 ` Erik Brandsberg <erik@heimdalldata.com>
1 sibling, 0 replies; 5+ messages in thread
From: Erik Brandsberg @ 2021-06-17 14:22 UTC (permalink / raw)
To: Sakshi Jain <sakshijain10388@gmail.com>; +Cc: pgsql-sql@lists.postgresql.org
Google for Postgres listen notify... ;) It is in the documentation.
On Thu, Jun 17, 2021 at 7:02 AM Sakshi Jain <sakshijain10388@gmail.com>
wrote:
> Hi Team,
>
> How to listen from within a psql process and get the payloads?
>
> Do Postgres have any such a mechanism where in a session a process send a
> "listen <name>" sql command and then gets a message if someone in the other
> session issued a "notify <name>".
>
> Please provide an example of how to do this.
>
> --
> *Thanks & Regards*
> Sakshi Jain
> New Delhi
> 8882433263
>
>
--
*Erik Brandsberg*
erik@heimdalldata.com
www.heimdalldata.com
+1 (866) 433-2824 x 700
[image: AWS Competency Program]
<https://aws.amazon.com/partners/find/partnerdetails/?n=Heimdall%20Data&id=001E000001d9pndIAA;
^ permalink raw reply [nested|flat] 5+ messages in thread
end of thread, other threads:[~2021-06-17 14:22 UTC | newest]
Thread overview: 5+ messages (download: mbox mbox.gz follow: Atom feed)
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2021-06-17 11:01 Listen and notify in psql process Sakshi Jain <sakshijain10388@gmail.com>
2021-06-17 11:04 ` Sakshi Jain <sakshijain10388@gmail.com>
2021-06-17 11:45 ` Ravi Krishna <srkrishna@yahoo.com>
2021-06-17 13:34 ` Torsten Förtsch <tfoertsch123@gmail.com>
2021-06-17 14:22 ` Erik Brandsberg <erik@heimdalldata.com>
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