Christof Petig <christof(at)petig-baender(dot)de> writes:
> COPY test (x) FROM stdin;
> 0.29999999999999999
> \.
This is not a bug; it's pg_dump trying to recreate the actual floating
point value as accurately as it can. See the discussion of
extra_float_digits from six months or a year back.
regards, tom lane