Jeff Janes <jeff.janes@gmail.com> writes:
> commit 1aba62ec made zero be an illegal value for effective_io_concurrency.
> i think this was an accident. If not, then the sample postgresql.conf
> (at least) needs to be updated.
It looks like the problem is that the new range check
+ /* This range check shouldn't fail, but let's be paranoid */
+ return (new_prefetch_pages > 0.0 && new_prefetch_pages < (double) INT_MAX);
should be testing for >= 0.0 not > 0.0.
regards, tom lane
