Re: Regarding NOTIFY

Yes, can do.  Just have an insert trigger on the jobs table that notifies the monitor, something like:

CREATE OR REPLACE FUNCTION notify_monitor()
RETURNS TRIGGER
LANGUAGE plpgsql
AS $$
    BEGIN
        NOTIFY monitor;
        RETURN NULL;
    END
$$

CREATE TRIGGER jobs_trigger
AFTER INSERT
ON jobs
FOR EACH STATEMENT
EXECUTE PROCEDURE notify_monitor();

Then all the monitor has to do is wait for notifications.  For C, see
http://www.postgresql.org/docs/9.1/static/libpq-notify.html
ruby-pg (the official ruby api to postgresql) has wait_for_notify(), which pretty much implements what the postgresql
docssuggest. 

Kiriakos
http://www.mockbites.com



On Mar 9, 2012, at 11:53 AM, Bret Stern wrote:

> We have a concrete batching application composed of two parts.
> 1. The Monitor.
> The Monitor cycles every 60 seconds, and looks into a Postgresql table
> for jobs to run. Primarily these jobs update Postgresql tables with
> data from external applications.
>
> 2. The Client.
> The client schedules orders etc.
>
> When a new product or customer is added to the Accounting or Batching
> Controller (both external applications; and databases) the Client user
> clicks a button and adds a job to run on the Monitor.
>
> Is it possible use the NOTIFY event to serve more like an interrupt,
> and trigger the Monitor to run immediately.
>
> Can it be used with VB?
> or
> Should I use LibPQ?
>
> Any suggestions welcome.
>
>
> If this is the wrong list for these questions, let me know?
>
> Bret Stern
>
>
>
>
>
>
>
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