Re: Progress report of CREATE INDEX for nested partitioned tables

I pushed 0001 with some cosmetic changes (for instance, trying to
make the style of the doc entries for partitions_total/partitions_done
match the rest of their table).

I'm not touching 0002 or 0003, because I think they're fundamentally
a bad idea.  Progress reporting is inherently inexact, because it's
so hard to predict the amount of work to be done in advance -- have
you ever seen a system anywhere whose progress bars reliably advance
at a uniform rate?  I think adding assertions that the estimates are
error-free is just going to cause headaches.  As an example, I added
a comment pointing out that the current fix won't crash and burn if
the caller failed to lock all the child tables in advance: the
find_all_inheritors call should be safe anyway, so the worst consequence
would be an imprecise partitions_total estimate.  But that argument
falls down if we're going to add assertions that partitions_total
isn't in error.

            regards, tom lane