Rodrigo Gonzalez wrote: 
> I am almost sure you've defined a BEFORE trigger and 
> you need and AFTER trigger, so it's fired after commiting.

No - I am definitely using an AFTER trigger. Following is a simplified
version of what I am trying to do.

/* messages - log messages */
CREATE TABLE messages
                (id             SERIAL PRIMARY KEY,
                        time            TIMESTAMP DEFAULT
CURRENT_TIMESTAMP,
                        severity_level  INTEGER NOT NULL,
                        severity        TEXT NOT NULL,  /*
ENUM('Info','Warning','Critical') */
                        facility        CHAR(10) NOT NULL,
                        msg             TEXT NOT NULL);

CREATE OR REPLACE FUNCTION message_alert() RETURNS TRIGGER AS
$message_alert$
        BEGIN
                PERFORM send_mesg('notify_channel', 'DB:Log:' || NEW.id
|| ':');
                RETURN NULL;
        END;
$message_alert$ LANGUAGE plpgsql;

CREATE TRIGGER message_alert AFTER INSERT ON messages
FOR EACH ROW 
EXECUTE PROCEDURE message_alert();

I have a Python program which is waiting on the message being sent via
send_mesg(). The message is received correctly but if I do an immediate
"SELECT msg FROM messages WHERE id=<the message id that came via the
send_msg() call>;" then it returns a NULL set. If I put a small sleep
between receiving the message and doing the select then I get the data.

What I want to do is to guarantee that the row is available for
selection prior to sending the message.

Mark



IMPORTANT: This email remains the property of the Australian Defence 
Organisation and is subject to the jurisdiction of section 70 of the CRIMES ACT 
1914.  If you have received this email in error, you are requested to contact 
the sender and delete the email.



-- 
Sent via pgsql-general mailing list (pgsql-general@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general

Reply via email to