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 ---------------------------(end of broadcast)--------------------------- TIP 9: the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match