Re: Listen / Notify - what to do when the queue is full - Mailing list pgsql-hackers

From Florian G. Pflug
Subject Re: Listen / Notify - what to do when the queue is full
Date
Msg-id 4B055B62.3020203@phlo.org
Whole thread Raw
In response to Re: Listen / Notify - what to do when the queue is full  (Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>)
Responses Re: Listen / Notify - what to do when the queue is full
List pgsql-hackers
Heikki Linnakangas wrote:
> Joachim Wieland wrote:
>> On Thu, Nov 19, 2009 at 4:12 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> Yes, I have been thinking about that also. So what should happen
>> when you prepare a transaction that has sent a NOTIFY before?
> 
> From the user's point of view, nothing should happen at prepare.
> 
> At a quick glance, it doesn't seem hard to support 2PC. Messages should
> be put to the queue at prepare, as just before normal commit, but the
> backends won't see them until they see that the XID has committed.

Yeah, but if the server is restarted after the PREPARE but before the 
COMMIT, the notification will be lost, since all notification queue 
entries are lost upon restart with the slru design, no?

best regards,
Florian Pflug


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