On K, 2005-06-29 at 11:02 -0400, Christopher Browne wrote:
> Victoria Parsons wrote:
> 
> > Hi,
...
> > Is there anything clever I can do other than setup replication, create
> > rules on slaves, remove the extra rules on slaves before
> > uniinistalling/changing master node, then recreate rules afterwards.
> >
> May I point you to the STORE TRIGGER command?
> 
> <http://linuxfinances.info/info/stmtstoretrigger.html>
> 
> That allows triggers to be "reactivated."

How does this relate to RULEs ?

Slony disables both triggers and rules, but provides only a command for
reactivating triggers.

> The effect there is that the triggers are applied to ALL nodes; that may
> not be exactly what you want.
> 
> It would be a neat idea to improve the STORE TRIGGER command so that
> triggers could be activated just on a particular set of nodes.

Same for EXECUTE SCRIPT - it would be much better, if the script couls
be executed onyl on a set of nodes (same as defined by a slony set).

> The challenging part would be to 'reshape' the triggers when something
> like MOVE SET is run.  It could take a fair bit of configuration
> information to handle that for general cases.  Indeed, configuring that
> to be handled "automagically" strikes me as requiring a pretty
> complicated configuration scheme :-(.

If this would be uniquely defined by a slony set, no additional info
would be needed.

> It's certainly not impossible; a carefully thought-out proposal for how
> to handle it needs to emerge...



-- 
Hannu Krosing <hannu at skype.net>