> 2. I am proposing the names stddev(x) and variance(x) for
> population and
> samplestddev(x) and
> samplevariance(x) for sample statistics. Any comments?
Other db's have:
stdev() for standard deviation sample (N-1)
variance() for variance computed from a sample (N-1)
> 3. I'm planning to implement this for types float4, float8
> and numeric. Any
> other types also? int[2,4,8] don't seem logical, as these
> would introduce
> serious rounding errors.
Integer would be good also. Do the arithmetic in numeric
to avoid loss of precision.
Andreas