Re: Bug: dblink_send_query not work on 9.2?

aasat <satriani(at)veranet(dot)pl> writes:
> This work

> do $$
> begin
> perform dblink.dblink_connect('internal');

I believe that creates an unnamed connection referencing a foreign
server definition named "internal".

> perform dblink.dblink_exec('internal', 'set application_name=''dblink'';',
> true);

This is going to find that "internal" is not the name of any known
dblink connection (since the one that does exist is unnamed). So it
creates a transient connection of its own using "internal" as a
connection string, ie a fresh reference to the foreign server. For the
duration of this command, there are two connections to the remote
database.

> perform dblink.dblink_disconnect();

And that closes the unnamed connection.

> perform dblink.dblink_send_query('internal', 'select dummy();');

This is going to fail because there is no dblink connection named
"internal". Unlike dblink_exec, there is no support for making a
transient connection for just the duration of the function call,
since it wouldn't be sensible --- the connection has to persist
so you can get the result back.

Use the two-parameter form of dblink_connect() so you can make a
named connection.

> It's works without problems on version 9.0

Consulting the commit logs, I see that that was a bug we fixed
as of 9.1.

Author: Joe Conway <mail(at)joeconway(dot)com>
Branch: master Release: REL9_2_BR [8af3596d6] 2011-06-25 15:58:07 -0700
Branch: REL9_1_STABLE Release: REL9_1_0 [e4fb58f89] 2011-06-25 15:40:49 -0700

Async dblink functions require a named connection, and therefore should
use DBLINK_GET_NAMED_CONN rather than DBLINK_GET_CONN.
Problem found by Peter Eisentraut and patch by Fujii Masao.

regards, tom lane