dblink_get_result issue

(Postgres 8.3.9)

oops, this is actually 8.4.4 on Windows.

-----Original Message-----
From: Marc Mamin
Sent: Mittwoch, 10. November 2010 18:25
To: 'pgsql-general@postgresql.org'
Subject: dblink_get_result issue

Hello,

I'm experimenting with dblink, and have an issue with async. queries
that do not return result sets.

(Postgres 8.3.9)

--youll need your own connect string to repeat:

select dblink_connect_u('myconn1', 'hostaddr=127.0.0.1 port=5432
dbname=postgres user=postgres password=x');

select dblink_send_query('myconn1', 'create temp table bah(s int8);');
select pg_sleep(.3);

SELECT * FROM dblink_get_result('myconn1', true ) as x (t text);

=>
********** Error **********
remote query result rowtype does not match the specified FROM clause
rowtype
SQL state: 42804

A subsequent call returns an empty result set, as described here:

http://www.postgresql.org/docs/8.3/interactive/contrib-dblink-get-result
.html

Thanks for any help.

Marc Mamin

"Marc Mamin" <M.Mamin@intershop.de> writes:

I'm experimenting with dblink, and have an issue with async. queries
that do not return result sets.

(Postgres 8.3.9)

--youll need your own connect string to repeat:

select dblink_connect_u('myconn1', 'hostaddr=127.0.0.1 port=5432
dbname=postgres user=postgres password=x');

select dblink_send_query('myconn1', 'create temp table bah(s int8);');
select pg_sleep(.3);

SELECT * FROM dblink_get_result('myconn1', true ) as x (t text);

=>
********** Error **********
remote query result rowtype does not match the specified FROM clause
rowtype

Hmm. I can reproduce this in 8.4 too, but it seems OK in 9.0. The only
one of the 9.0 commits that seems likely to be relevant is
http://git.postgresql.org/gitweb?p=postgresql.git;a=commitdiff;h=56cbb611ec749ba867a4cfc09c8b7df0f4446620

which looks a bit overcomplex for a back-patch. Joe, any thoughts?

regards, tom lane

For now I just ignore the first exception.

BEGIN
PERFORM * from dblink_get_result('myconn')as x (t text);
EXCEPTION WHEN datatype_mismatch THEN NULL;
END;
PERFORM * from dblink_get_result('myconn')as x (t text);

thanks,

Marc Mamin

-----Original Message-----
From: Tom Lane [mailto:tgl@sss.pgh.pa.us]
Sent: Donnerstag, 11. November 2010 00:54
To: Marc Mamin
Cc: pgsql-general@postgresql.org; Joe Conway
Subject: Re: [GENERAL] dblink_get_result issue

"Marc Mamin" <M.Mamin@intershop.de> writes:

I'm experimenting with dblink, and have an issue with async. queries
that do not return result sets.

(Postgres 8.3.9)

--youll need your own connect string to repeat:

select dblink_connect_u('myconn1', 'hostaddr=127.0.0.1 port=5432
dbname=postgres user=postgres password=x');

select dblink_send_query('myconn1', 'create temp table bah(s

int8);');

select pg_sleep(.3);

SELECT * FROM dblink_get_result('myconn1', true ) as x (t text);

=>
********** Error **********
remote query result rowtype does not match the specified FROM clause
rowtype

Hmm. I can reproduce this in 8.4 too, but it seems OK in 9.0. The only
one of the 9.0 commits that seems likely to be relevant is
http://git.postgresql.org/gitweb?p=postgresql.git;a=commitdiff;h=56cbb61
1ec749ba867a4cfc09c8b7df0f4446620

which looks a bit overcomplex for a back-patch. Joe, any thoughts?

regards, tom lane

On 11/10/2010 03:54 PM, Tom Lane wrote:

"Marc Mamin" <M.Mamin@intershop.de> writes:

SELECT * FROM dblink_get_result('myconn1', true ) as x (t text);

=>
********** Error **********
remote query result rowtype does not match the specified FROM clause
rowtype

Hmm. I can reproduce this in 8.4 too, but it seems OK in 9.0. The only
one of the 9.0 commits that seems likely to be relevant is
http://git.postgresql.org/gitweb?p=postgresql.git;a=commitdiff;h=56cbb611ec749ba867a4cfc09c8b7df0f4446620
which looks a bit overcomplex for a back-patch. Joe, any thoughts?

Sorry for the slow response.

I think this issue was fixed by that patch only as a side effect of
significant restructuring. The attached one liner against 8.4 seems to
fix it. Objections?

Joe

--
Joe Conway
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