Tom Lane wrote:
In the integer-timestamp world we know that the number is exact in
microseconds. We clearly ought to be prepared to display up to six
fractional digits, but suppressing trailing zeroes in that seems
appropriate.
Great.
We could try to do the same in the float case, but I'm a bit worried
about finding ourselves showing "1234567.799999" where it should be
"1234567.8".
If I understand the code right fsec should mostly be values
between -1 and 1 anyway, because even in the floating point
case seconds are carried in the tm->tm_sec part.
It looks to me that a double should be plenty to do
microseconds so long as we don't put big numbers into fsec.
printf("%.99f\n",59.111111111111111111);
59.11111111111111426907882 ...
Anyway - I'll try showing up-to-6-digits in both cases and
seeing if I can find a test case that breaks.
I guess this rounding trickiness with rounding explains some of
the bizarre code like this too:
#if 0
/* chop off trailing one to cope with interval rounding */
if (strcmp(str + len - 4, "0001") == 0)
{
len -= 4;
*(str + len) = '\0';
}
#endif
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