Re: Problems with autovacuum

Alvaro Herrera <alvherre@commandprompt.com> writes:
> Tom Lane escribi�:
>> Hmm, maybe we need to improve the code too.  This example suggests that
>> there needs to be some limit on the worker launch rate, even if there
>> are so many databases that that means we don't meet naptime exactly.

> We already have a 100ms lower bound on the sleep time (see
> launcher_determine_sleep()).  Maybe that needs to be increased?

Maybe.  I hesitate to suggest a GUC variable ;-)

One thought is that I don't trust the code implementing the minimum
too much:

    /* 100ms is the smallest time we'll allow the launcher to sleep */
    if (nap->tv_sec <= 0 && nap->tv_usec <= 100000)
    {
        nap->tv_sec = 0;
        nap->tv_usec = 100000;    /* 100 ms */
    }

What would happen if tv_sec is negative and tv_usec is say 500000?
Maybe negative tv_sec is impossible here, but ...

            regards, tom lane