Re: Resetting libpq connections after an app error

On Sat, Jul 21, 2012 at 01:08:58AM +0100, Daniele Varrazzo wrote:
> Hello,
>
> apologize for bumping the question to -hackers but I got no answer
> from -general. If there is a better ML to post it let me know.
>
> In a libpq application, if there is an application error between
> PQsendQuery and PQgetResult, is there a way to revert a connection
> back to an usable state (i.e. from transaction status ACTIVE to IDLE)
> without using the network in a blocking way? We are currently doing
>
>     while (NULL != (res = PQgetResult(conn->pgconn))) {
>         PQclear(res);
>     }
>
> but this is blocking, and if the error had been caused by the network
> down, we'll just get stuck in a poll() waiting for a timeout.

There is PQreset(), which also exists in a non-blocking variant.

Hope this helps,
--
Martijn van Oosterhout   <kleptog@svana.org>   http://svana.org/kleptog/
> He who writes carelessly confesses thereby at the very outset that he does
> not attach much importance to his own thoughts.  -- Arthur Schopenhauer