Message-ID: <3E4B1CB7.90309@joeconway.com>
Date: Wed, 12 Feb 2003 20:19:03 -0800
From: Joe Conway <mail@joeconway.com>
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To: Frankie Lam <frankie@ucr.com.hk>
Cc: pgsql-sql@postgresql.org
Subject: Re: dblink question please
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Frankie Lam wrote:
> Does anyone know if there's a simple way that let dblink function calls in a
> plpgsql function wouldn't raise exception, in case there's sth wrong.
> (e.g. cannot connect to the remote host ......)

Not without hacking dblink.c.

At quick glance it looks like it might be reasonably safe to use
dblink_connect with the lines:

8<---------------------------------
if (PQstatus(persistent_conn) == CONNECTION_BAD)
{
    msg = pstrdup(PQerrorMessage(persistent_conn));
    PQfinish(persistent_conn);
    persistent_conn = NULL;
    elog(ERROR, "dblink_connect: connection error: %s", msg);
}
8<---------------------------------

changed to something like (untested)

8<---------------------------------
if (PQstatus(persistent_conn) == CONNECTION_BAD)
{
    msg = pstrdup(PQerrorMessage(persistent_conn));
    PQfinish(persistent_conn);
    persistent_conn = NULL;
    elog(NOTICE, "dblink_connect: connection error: %s", msg);
    result_text = DatumGetTextP(DirectFunctionCall1(textin,
                                   CStringGetDatum("ERROR")));
    PG_RETURN_TEXT_P(result_text);
}
8<---------------------------------

It would be more complex if you want to not use the persistent connection.

HTH,

Joe