On 7/19/2007 12:58 AM, Mikko Partio wrote:
> Hello all,
> 
> I have to set up a replica of our production database to a possibly 
> insecure location (DMZ). I have been using slony in other projects and 
> the log shipping mode would seem to fit this purpose perfectly, but, 
> alas, it requires that another slave is configured besides the origin 
> node. This is not very practical for us since the replicated database is 
> large and we don't have the hardware to support yet another slave. So, 
> my question is that is there any way to configure log shipping with just 
> the origin and the log shipping slave?

No, only the slon of a real replica can actually write the log files. 
However, what might work in your case is to create a "fake" replica. 
Create a replica that has a slave-only trigger (using STORE TRIGGER) on 
every replicated table. The trigger fires BEFORE INSERT and all it does 
is RETURN NULL. And you subscribe the thing with no forwarding. That 
should create an empty replica that now can write the log shipping 
files. To get the initial content for the offline replica you must 
however stop the application and dump from the origin.

> 
> On a side note, I saw recently some discussion about the privileges of 
> the replication user, namely that the superuser mode is only required at 
> the initial subscription. Can I just ALTER USER x NOSUPERUSER when in 
> "normal" replication mode?

Not even that. Each slon only needs superuser access to its local node. 
Never does it need privileged access to the remote side. And all remote 
access is read only.


Jan

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