Re: [Plproxy-users] A complex plproxy query - Mailing list pgsql-general

From Hannu Krosing
Subject Re: [Plproxy-users] A complex plproxy query
Date
Msg-id 1232587577.8708.4.camel@huvostro
Whole thread Raw
In response to A complex plproxy query  (Igor Katson <descentspb@gmail.com>)
Responses Re: [Plproxy-users] A complex plproxy query
List pgsql-general
On Thu, 2009-01-22 at 02:33 +0300, Igor Katson wrote:

> So to say, give me the list of friends (not only their ID's, but all the
> needed columns!) of given individual, which are in a given group. That
> seems ok without plproxy, but with using it, I can't imagine how can I
> form a nice query, or a function (or a set of plpgsql + plproxy
> functions) to do the job.

You need to do it in two steps - first run a query on the partition the
user is in to get list of friends ids, then run a second RUN ON ALL
query with

WHERE f.friend.id in (list of ids from f1) AND f.group_id = $2

to gather all friend info in parallel

--
------------------------------------------
Hannu Krosing   http://www.2ndQuadrant.com
PostgreSQL Scalability and Availability
   Services, Consulting and Training


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