Re: FDW wrapper for clustered app management

Jerome Wagner wrote:
> I am considering (postgres 9.3+) the idea of opening a R/W access into a clustered application by
> creating one fdw server from a central database to each server a cluster.
>
> That would imply opening a port on each server inside the application, listening for incoming
> connections from the database and this way all the servers would become visible with R/W access.
>
> Is that a sound idea or does it look horrible ? Would it be reasonable to connect in this way to a
> cluster of 1, 10, 100, 1000 or more servers ?
>
> is there an existing xxxx_fdw wrapper that would look like a good candidate for such a direct access
> inside an application ? Then I would have to implement the protocol corresponding to this xxxx_fdw
> inside my application.

What is the application you want to access this way?

Does "cluster" mean that data is distributed (sharded) across these servers?

Can you reasonably translate SQL access predicates so that you can push down
WHERE conditions to the remote servers? If not, every access would have to pull
the entire foreign table into the PostgreSQL server before applying the conditions.

Under the right conditions, such a setup could work, e.g. to join data from
different data sources. How many servers make sense probably depends a lot on how
you want to use them.

Yours,
Laurenz Albe