Re: Simple SQL INSERT to avoid duplication failed: why?

-----Original Message-----
From: pgsql-general-owner(at)postgresql(dot)org [mailto:pgsql-general-owner(at)postgresql(dot)org] On Behalf Of Jasen Betts
Sent: May 4, 2013 7:44 PM
To: pgsql-general(at)postgresql(dot)org
Subject: Re: [GENERAL] Simple SQL INSERT to avoid duplication failed: why?

On 2013-05-01, Carlo Stonebanks <stonec(dot)register(at)sympatico(dot)ca> wrote:
> There are no client poolers (unless pgtcl has one I don't know about)
> so this is unlikely.
>
> The trigger is an interesting idea to try if it happens again - I
> can't keep it for long as it is for a massive cache (used to deflect
> calls to a web
> service) and will bloat the logs pretty quickly.
>
> I have to ask myself, is it more likely that I have discovered some PG
> anomaly in 9.0 that no one has ever noticed, or that the client has
> accidentally launched the process twice and doesn't know it?

>> If it's running on a web server and two clients send the same request simultaneously could that cause it to try the >> same task twice simultaneously?

It would, but it's not running on a web server. It's a kind of dedicated data warehouse with very limited access. No programs have the right to write to the tables other than the one in question.