| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | Joachim Wieland <joe(at)mcknight(dot)de> |
| Cc: | Jeff Davis <pgsql(at)j-davis(dot)com>, Greg Smith <greg(at)2ndquadrant(dot)com>, Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>, "Florian G(dot) Pflug" <fgp(at)phlo(dot)org>, Josh Berkus <josh(at)agliodbs(dot)com>, pgsql-hackers(at)postgresql(dot)org |
| Subject: | Re: Listen / Notify - what to do when the queue is full |
| Date: | 2010-01-20 16:14:23 |
| Message-ID: | 13382.1264004063@sss.pgh.pa.us |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
Joachim Wieland <joe(at)mcknight(dot)de> writes:
> On Wed, Jan 20, 2010 at 1:05 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> I guess Joachim is trying to provide a similar guarantee for the new
>> implementation, but I'm not clear on why it would require locking.
> It is rather about a listening backend seeing a notification in the
> global queue without knowing if it should deliver the notification to
> its frontend or not. The backend needs to know if its own LISTEN
> committed before or after the NOTIFY committed that it sees in the
> queue.
In that case I think you've way overcomplicated matters. Just deliver
the notification. We don't really care if the listener gets additional
notifications; the only really bad case would be if it failed to get an
event that was generated after it committed a LISTEN.
regards, tom lane
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Tom Lane | 2010-01-20 16:17:23 | Re: Git out of sync vs. CVS |
| Previous Message | Tom Lane | 2010-01-20 16:03:27 | Re: lock_timeout GUC patch |