Re: PQstatus does not seem to work

On 8/10/09 12:08 PM, "Sam Mason" <sam(at)samason(dot)me(dot)uk> wrote:

> On Tue, Aug 11, 2009 at 12:41:47AM +0800, Juan Backson wrote:
>> I used PQstatus(conn) function to check connection status, but I found that
>> it still returns CONNECTION_OK even after postgres is restarted. Does
>> anyone know if there is another command that I can use to check connection
>> status?
>
> Yes, PQstatus just gives back the last status. It doesn't go off and
> check anything.
>
>> What other solution is available to check whether a connection is still
>> alive?
>
> As a connection can go down at any time, this doesn't seem useful. Just
> send off your request as normal and if it fails because the connection
> was closed then you can open a new one and try again.

Depending on your situation, connection pooling might be a reasonable
option. Instead of managing the connections yourself, you leave that to
another process entirely.

http://www.revsys.com/writings/postgresql-performance.html

Look at the section on "Stateless Applications"

I spend a lot of time writing stateless apps that server many 'users'
concurrently. For me, the pooling idea is much simpler because I only
interact with the 'pool', and the pool manages opening and closing
connections on my behalf.

Of course, this is not a good option if you're writing a stateful app. Your
original email didn't say either way, so this is a take on the other side of
the problem.