Обсуждение: triggers

hi

I have a query regarding triggers.
On INSERT, UPDATE, DELETE I want to fire a trigger to relect it to another database on postgres sever.
how can I do this operation.

Thanks in advance,
Kailash Vyas

--
"Adopting the position that you are smarter than an automatic
optimization algorithm is generally a good way to achieve less
performance, not more" - Tom Lane.

On Thu, 8 Sep 2005, Kailash Vyas wrote:

> hi
>
> I have a query regarding triggers.
> On INSERT, UPDATE, DELETE I want to fire a trigger to relect it to another
> database on postgres sever.
> how can I do this operation.

This is tricky, because you probably want to have the same transactional
occurances as well (ie, rollbacks not leaving the rolledback data on the
other database).  You might be best off looking at some of the replication
systems for PostgreSQL to see what they do (or perhaps just using one).

kailash.vyas@gmail.com (Kailash Vyas) writes:
> hi
> I have a query regarding triggers.
> On INSERT, UPDATE, DELETE I want to fire a trigger to relect it to another database on postgres sever.
> how can I do this operation.
> Thanks in advance,
> Kailash Vyas

If you wish the trigger to result in some action taking place on
another database, then there are two major methodologies available:

 1.  The trigger could RAISE an event.

     A LISTENing daemon would see that event, and do something in the
     other database.

 2.  The trigger could write data into a replicated table.

     The replication system (possibly Slony-I?) would then copy
     the replicable data to the other database.

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