Re: pgsql: Increase upper limit for vacuum_cleanup_index_scale_factor

Alexander Korotkov <a(dot)korotkov(at)postgrespro(dot)ru> writes:
> BTW, this line looks cumbersome.

> +DETAIL: Valid values are between "0.000000" and
> "179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368.000000".

> It's not something introduced by this patch, because other reloptions
> behave the same. Should we change output format for real reloption
> boundaries to '%g' (as guc.c does). It looks much better.
> ERROR: -1 is outside the valid range for parameter "random_page_cost"
> (0 .. 1.79769e+308)

%g, unmodified, is a bad idea because it loses a lot of precision
in some cases (due to the assumption that nobody cares about more
than six digits). Maybe you could fix that by using %.15g or some
such, but...

I think that the original patch to use DBL_MAX was itself a bad idea
and should be rethought. It creates (what is in principle) a
platform-dependent limit, for no adequate justification. Why not
just set it to 1e9 or 1e10 or some such?

regards, tom lane