Re: [Postgres-xc-general] is it possible to connect a (postgresql) data node server directly (not using coordiantor)

[Michael P. <mic...@gm...>]

On Wed, Jul 4, 2012 at 2:38 PM, Aris Setyawan <ari...@gm...> wrote:

> Hi All,
>
> > Hi Aris,
> > We found that documents were not updated. WITH clause is supported in
> XC. Please try
> > to use it and let us know if it doesn't work for you. Thanks for
> pointing it out.
>
> But how the coordinator will split the WITH clause (recursive) query?
> If the query wrongly splitted, then many cross datanode join will occurred.
> This is a well known issue in a graph partitioned database.
>
XC planner is pretty smart, all the clauses are analyzed at the Coordinator
level.
Then only the necessary clauses and expressions are shipped to the
necessary remote nodes depending on the table distribution.
It may be possible that a lot of data is fetched back to Coordinator, but
this depends on how you defined the table distribution strategy of your
application.
-- 
Michael Paquier
http://michael.otacoo.com