Re: implementing asynchronous notifications - Mailing list pgsql-jdbc

From Oliver Jowett
Subject Re: implementing asynchronous notifications
Date
Msg-id 4266E296.6050105@opencloud.com
Whole thread Raw
In response to Re: implementing asynchronous notifications  (David Gagnon <dgagnon@siunik.com>)
Responses Re: implementing asynchronous notifications PLEASE CONFIRM MY
List pgsql-jdbc
David Gagnon wrote:

>  I just read this thread. Wich seems really interesting.  Is there an
> example on how to use Async Notifies?  I look at it a couple of months
> ago and found it not sufficient for my needs.  I need to implement a
> notification mechanism to clear data from caches in my application on
> data update.
>
> Is this change allow me to do that .. ?  That will be so nice :-)
>
> If yes it's that possible to get a small example on how to use it.

Basically, you can now call PGConnection.getNotifications() and get
results without having to submit a dummy query first.

You will still need an application-level loop that periodically calls
it, though. Also, it's not guaranteed to give you notifications: you
must be not in a transaction (this is server-side behaviour), and you
must be using a Socket implementation that implements available() (SSL
connections may not do this).

-O

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