jdbc: Asking the DB-server for a notification

On Dec 27, 1:58 am, Arne Vajhøj <a....DeleteThis@vajhoej.dk> wrote:
> --(update)--database X--(trigger)--some MQ--(JMS)--Java app
>
> --(update)--database X--(trigger in Java)--(socket)--Java app
>
> Arne

Hmm...interesting. A simple google search obviously didn't turn up
anything of interest.

Any links on this would be really appreciated.

Regards,
/sasuke.
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sasuke wrote:
> Hmm...interesting. A simple google search obviously didn't turn up
> anything of interest.
>
> Any links on this would be really appreciated.

Well, all servers nowadays allow custom extensions to offer new functions
available in SQL.

One could implement such a function, which will be called from the trigger
and notify the client program somehow -- "out of band".

That's Arne's idea, and it is doable.

However, I was hoping, something more uniform is already available, but that
does not seem to be the case

-mi
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TwelveEighty wrote:
> On Dec 27, 11:23 am, Mikhail Teterin <usenet+m...@aldan.algebra.com>
> wrote:
>> One could implement such a function, which will be called from the trigger
>> and notify the client program somehow -- "out of band".
>>
>> That's Arne's idea, and it is doable.
>>
>> However, I was hoping, something more uniform is already available, but that
>> does not seem to be the case
>
> I would solve this a little further upstream, if possible. What, for
> example, causes the table to change? Is there someone or something
> that creates a transaction that enters data? Could your program become
> the "business logic" layer that sits in between that and the database?

Isn't this the sort of thing they invented BPEL for?

The insight is that business processes interlock and interact. A process
control system, perhaps with a process control language like BPEL gluing
things together, orchestrates the various business processes that must
coordinate, as in this case, a web application and a database application.

Custom programming can do the same thing. I suspect that thinking of the
custom system as a business-process orchestrator would be useful.

This is a problem space that has been approached for decades, and for which
there are many buzzwords, none of which seem to have emerged as a clear winner.

--
Lew
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