Re: reducing statistics write overhead

I wrote:
> No, no, no.  Martin already had a perfectly sane design for that
> direction of signalling: send a special stats message to the collector.

Actually ... given that the stats message mechanism is designed to be
lossy under high load, maybe that isn't so sane.  At the very least
there would have to be timeout-and-resend logic on the backend side.

I dislike the alternative of communicating through shared memory,
though.  Right now the stats collector isn't even connected to shared
memory.
        regards, tom lane