--- On Tue, 12/11/07, Matthew Dennis <mdennis@xxxxxxxxxx> wrote: > http://www.postgresql.org/docs/8.3/static/sql-createaggregate.html > is for > 8.3 where there were some changes to the number of > arguments an aggregate > could take. I believe it's also more descriptive > documentation. > > of course for things like average you wouldn't need a > custom type... Thanks for the information it is very useful. The reason that I ask, is that I am trying to develop a way to calculate the average power factor(scalar) of a Motor Control Center (among other things). The Electrical Engineers that are asking for the report introduced me to a rather complicated formula to implement in standard SQL. The best way that I can describe the problem get the PF is finding the angle between Xcomp/hypotenuse after having used Pythagorean theorem to find the hypotenuse after having summing of multiple 2 coordinate vectors(the EEs use the term phasers) for each MCC cubical. It seems they have need for quite a few other little aggregate functions that they would like me to make if I can get this one done first. Anyway thank for the push in the right direction! Regards, Richard Broersma Jr. Anyway ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend
