Kemin,
> Just noticed that the postgres stddev is the stddev_sample formula.
> There are two different ways to calculate this value.
> Their difference is very small with large samle size. It would be nice
> to distinguish the two different versions.
Note sent to PGSQL-DOCS.
> I also noticed that oracle has stddev_sample and stddev_population.
> This is just a wish list.
Were you aware that in PostgreSQL you can write your own aggregates? It's
relatively easy to do.
--
Josh Berkus
Aglio Database Solutions
San Francisco