Is there a big performance difference between AVG and MEDIAN? I can certainly see that mathematically MEDIAN would be much slower considering that it has to sort, but I tested out some queries and didn't notice much difference, but maybe my dataset was too small to notice.
I imagine that PERCENTILE would have nearly the same performance cost as MEDIAN...is that true? Michael On Tue, Oct 23, 2012 at 11:39 AM, K. John Wu <[email protected]> wrote: > Hi, Michael, > > This sounds like an interesting new aggregation function. My time is > fully committed for the next few months, so I might not be able to > implement this feature. If you can code up something, we'd be happy > to put it in FastBit.. > > By the way, this aggregation similar to median would not be able to be > processed by parts. Therefore this would be an expensive operator. > > John > > > On 10/23/12 10:47 AM, Michael Beauregard wrote: >> Hey John, >> >> I looked through the source code and didn't find support for a >> PERCENTILE (or similar) aggregation function, but it appears that it >> conceptually wouldn't be too hard to build one as a generalize form >> the existing MEDIAN aggregation. To validate my thinking with you, I >> imagine that PERCENTILE would take one additional argument indicating >> what percentile to return. Unless I'm mistaken, it seems that MEDIAN >> could then be implemented as PERCENTILE(50, <columns>) internally. >> >> What are your thoughts on this feature? >> >> Michael >> _______________________________________________ >> FastBit-users mailing list >> [email protected] >> https://hpcrdm.lbl.gov/cgi-bin/mailman/listinfo/fastbit-users >> _______________________________________________ FastBit-users mailing list [email protected] https://hpcrdm.lbl.gov/cgi-bin/mailman/listinfo/fastbit-users
