Andrew Sullivan wrote:
> Dane Miller wrote:
> > Consider the below example. Does Slony guarantee that the updated
> > sequence will always appear after (or concurrently with) the result
> > of the I/U/D statements on subscriber nodes?
> 
> Not necessarily.  Slony sets the sequence on the target to the value
> of the sequence at the time of the sync, because there isn't any other
> way to look at the sequence value.  The idea is that it's ok for a
> sequence to be _ahead_ of the rest of the database, because this is
> consistent with the semantics of sequences in an unreplicated database
> (they always advance, so they're never-go-backwards series that
> possibly have gaps).  
> 
> If you want this, you could probably do it using a table that is
> replicated and that gets updated with currval() using a trigger or
> something. 

Thanks very much Andrew.  I think this explains errors we are seeing on
supposedly up-to-date subscriber nodes.

I think storing currval() in a table, as you suggest, looks promising...
perhaps using TRUNCATE before each insert to avoid dead tuple bloat.

Dane
-- 
Dane Miller
Systems Administrator
Greatschools, Inc
http://www.greatschools.net