Marko Kreen wrote:
On 1/22/09, Igor Katson <descentspb@xxxxxxxxx> wrote:
Hannu Krosing wrote:
> 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
>
>
I was thinking about that. But I don't understand, how can I pass the
list of id's. Should I turn the output of a select into an array? How
then? What if the array gets hundreds of items long?
Yes, array works fine. And if it's long, then let it be long...
Ok, thank you, guys. What is the best way to make an array out of a
column? I didn't make up anything better then writing a function:
CREATE OR REPLACE FUNCTION int_column_to_array(query text) RETURNS int[]
AS $$
DECLARE
arr int[];
rec int;
BEGIN
FOR rec IN EXECUTE query
LOOP
arr := array_append('{}',rec);
END LOOP;
RETURN arr;
END;
$$ language plpgsql;
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