> While computing standard deviation on a float8 column, I noticed that
> sometimes STDDEV returned "NaN". I've tracked down the cause and
> thought I'd show everyone. This may or may not be a bug, I don't know.
This was fixed for PostgreSQL version 7.2 afaict. Time to upgrade if you
are not running that version, and let us know if you already are running
it and we'll look into it further.
fwiw, I cannot reproduce the problem on my Linux box running 7.2.
Regards.
- Thomas