yes, you are correct On Thu, Oct 11, 2018 at 6:24 AM Abhishek Kaushik <akaushik...@gmail.com> wrote:
> So, something like this should work then: > > "aggregations":[ > { > "fieldName":"metric1", > "name":"metric1", > "type":"longSum" > }, > { > "fieldName":"metric2", > "name":"metric2", > "type":"longSum" > } > ], > "postAggregations":[ > { > "name":"result", > "fn":"+", > "type":"arithmetic", > "fields":[ > { > "fieldName":"metric1", > "name":"metric1", > "type":"fieldAccess" > }, > { > "fieldName":"metric2", > "name":"metric2", > "type":"fieldAccess" > } > ] > } > ], > ... > "metric": "result" > ... > as the config. > > On Thu, Oct 11, 2018 at 6:49 PM Charles Allen > <charles.al...@snap.com.invalid> wrote: > > > For the vast majority of use cases, Yes! For example, lets say you have > two > > metrics "Cost" and "Taxes" as USD cents. When you add the two together > you > > get the total that was charged (or something similar). > > > > To get the total that was charged across everything, you simply sum the > > Cost and sum the Taxes as aggregators, then do what's called a > > post-aggregator to sum those two aggregators. > > > > The place where this DOESN'T work well is if Cost is is local monies, and > > you want to convert every event to USD and then sum them. The easiest > way I > > know to handle such a thing is to do the conversion during your initial > > data cleanup and processing. An example on a similar vein is if you want > to > > do "inflation adjusted USD". For these two scenarios I'd really have to > > think about if there's a clean way to do the calculation; no immediate > one > > comes to mind. In these scenarios the way I can think of would be: > > > > A) Do a topN (or groupBy) against the currency type, then do some client > > side aggregation to convert the per-currency result into a constant > > currency value > > B) Do a timeseries, and do the per-time-bucket conversion on the client > > side, then do the final aggregation on the client side as well. > > > > Hopefully that clarifies things a bit. > > > > > > On Thu, Oct 11, 2018 at 6:07 AM Abhishek Kaushik <akaushik...@gmail.com> > > wrote: > > > > > Hi, > > > Suppose I have two metrics A and B in my dataset. I need to have a TopN > > > query on the aggregated combination of both (here A+B). Is it possible > in > > > druid? > > > > > >