Re: Connecting to NOTIFY with telnet

Jeff,

On Sat, May 4, 2019 at 11:34 AM Jeff Janes <jeff(dot)janes(at)gmail(dot)com> wrote:

> On Sat, May 4, 2019 at 1:49 PM Igal Sapir <igal(at)lucee(dot)org> wrote:
>
>> Christoph,
>>
>> On Sat, May 4, 2019 at 10:44 AM Christoph Moench-Tegeder <
>> cmt(at)burggraben(dot)net> wrote:
>>
>>> ## Igal Sapir (igal(at)lucee(dot)org):
>>>
>>> > My main "issue" is that the official pgjdbc driver does not support the
>>> > notifications with listen and I was trying to figure out why.
>>>
>>> https://jdbc.postgresql.org/documentation/head/listennotify.html
>>>
>>>
>> I should have been more explicit. My main issue is with the following
>> statement from the link that you posted:
>>
>> > A key limitation of the JDBC driver is that it cannot receive
>> asynchronous notifications and must poll the backend to check if any
>> notifications were issued
>>
>> Polling is much less efficient than event handling and I'm sure that
>> there's a major performance hit with that.
>>
>
> Isn't that addressed here?:
>
> // If this thread is the only one that uses the
> connection, a timeout can be used to
> // receive notifications immediately:
> // org.postgresql.PGNotification notifications[] =
> pgconn.getNotifications(10000);
>
>
It "helps", but it's still not the same as keeping the connection open and
receiving messages in real time.

Looking at the documentation of pgjdbc-ng [1] it looks quite impressive.
I'm thinking to try it out and possibly even try to benchmark it for
performance against the official JDBC driver.

Igal

[1]
http://impossibl.github.io/pgjdbc-ng/docs/current/user-guide/#extensions-notifications

> Cheers,
>
> Jeff
>
>>