Joe Conway wrote: > > Do you think there would be any use for an aggregate which returns an > > array of the aggregated (usually simple) type?
>What exactly have you looked at? In current cvs there is array_append >and array_cat. There *was* array_accum, but that was yanked due to an >objection that it was redundant with the other two. Actually, I was looking at array_set, which has a provision to grow a 1d array. I was looking at the 7.3.2 sources, so it's pretty clear I would have to look at something newer. I'll wait for 7.4. >BTW, I tried array_accum() (which is not really much different than >array_append()) with groups of about 10,000 elements and feeding the >array into a plr final function for a mean calculation. It was for sure >slow compared to a native AVG() aggregate, but it wasn't that bad >either. I don't remember the specifics, but it would be easy enough to >try it out for yourself. Well, if dynamic growth is expected, there are some easy optimizations that could reduce the time spent reallocating the array. If there was a detectable difference vs. the avg() function, which performs zero reallocations, its probably worthwhile. Based on what I saw with the older source, I assumed there was little or no dynamic growth in normal use. > No one is currently working on it that I'm aware of, but I was > considering working on it for 7.5 By all means! What do you think about the other question about an 'array creating aggregate', is that a useful contribution? Joe ---------------------------(end of broadcast)--------------------------- TIP 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED]
