...Robert
On Jun 2, 2009, at 10:38 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Robert Haas <robertmhaas@gmail.com> writes:
>> On Jun 2, 2009, at 9:41 AM, Simon Riggs <simon@2ndQuadrant.com>
>> wrote:
>>> You're right that the number of significant digits already exceeds
>>> the
>>> true accuracy of the computation. I think what Robert wants to see
>>> is
>>> the exact value used in the calc, so the estimates can be checked
>>> more
>>> thoroughly than is currently possible.
>
>> Bingo.
>
> Uh, the planner's estimate *is* an integer. What was under discussion
> (I thought) was showing some fractional digits in the case where
> EXPLAIN
> ANALYZE is outputting a measured row count that is an average over
> multiple loops, and therefore isn't necessarily an integer. In that
> case the measured value can be considered arbitrarily precise ---
> though
> I think in practice one or two fractional digits would be plenty.
We're in violent agreement here.
...Robert