Re: ALTER TABLE ... ALTER COLUMN ... SET DISTINCT

Robert Haas <robertmhaas@gmail.com> writes:
> Well, I think I was pretty clear about what I was trying to
> accomplish.  I think there are more people who care about pg_dump
> output being diffable than there are who need to set ndistinct more
> accurately than 1 ppm and yet not as an integer.

My, you *are* paranoid about float4 aren't you?  Once you've stored
a given value, it's always going to dump the same.  Diffing different
dumps isn't going to be a problem.  I concede that it might look
different from what you put in originally, but we make no effort to
guarantee that for DDL anyway.

(It is true that with pg_dump's default float_extra_digits setting,
outputs from this column might look uglier than they need to.
I don't see anything wrong with having pg_dump forcibly round the
value to five or so digits, though.)
        regards, tom lane