Re: Backend message type 0x50 arrived while idle

On Tue, 3 Dec 2002, Wynn, Robin wrote:

> I know... the problem is two-fold. One, I had to have that in writing so I
> could justify upgrading, and two, we release in a few days and can't really
> change the database until that's complete (requires too many changes to
> existing things). I was just hoping someone here would know what that
> message meant so I could either document it, or prove it's not the database
> that's got a problem, it's our interaction with it. I've seen a number of
> people ask this question on a number of different versions of PostgreSQL (I
> believe the latest I've seen is 7.1.x), so I suspect that it's something
> we're doing... I just need to know what that message means, so I know how to
> troubleshoot it on our end. It's not incredibly descriptive :^P
>

OK, I was just wandering around the source code, and this same error can
happen in 6.5.x or 7.3.whatever.

The docs inside the source of
postgresql-7.3/src/interfaces/libpq/fe-exec.c say:

/*
* NOTIFY and WARNING messages can happen in any state besides
* COPY OUT; always process them right away.
*
* Most other messages should only be processed while in BUSY state.
* (In particular, in READY state we hold off further parsing
* until the application collects the current PGresult.)
*
* However, if the state is IDLE then we got trouble; we need to deal
* with the unexpected message somehow.
*/

And:

/*
* Unexpected message in IDLE state; need to recover somehow.
* ERROR messages are displayed using the notice processor;
* anything else is just dropped on the floor after displaying
* a suitable warning notice. (An ERROR is very possibly the
* backend telling us why it is about to close the connection,
* so we don't want to just discard it...)
*/

So, are there any other messages to go with this error?

Are you using libpq to interface? It sounds like maybe your client app is
sending data when it shouldn't.