Re: how do you write aggregate function

Array appends are usually a performance hit, as you said. I'm not sure
though with
PostgreSQL. Why not try it with two arrays and see what happens. At
least you would
reducing the single array and the eliminating the append.

danap.

> I got the aggregate function for weighted average done. I finely
> left alone for more than 10 minutes to actual get it written. It
> takes 2 value input Weight and the Value. it will sum the weighted
> entries to create the constant then does the normal formula, but does
> not percentage number but averaged number. A simple change on the
> return line it can do percentages.
>
> I did a couple of things a little odd . instead of doing a multi
> dimensional array i did a one dimensional array where the 1st row is
> Weight and the 2nd row is Value. This made the loop through the
> array look stupid.
> I tested it across 50,000 records with a group by it took 3.3 seconds
> to run.
>
> without the group by clause performance is terrible taking several
> minutes just to do the sfunc part. 371,563ms
>
> The Array seems to have performance hit any advice? It could be the
> way i'm appending to the Array which has a performance hit as the
> array gets bigger and bigger ?