How to do calculations/ comparisons on 2 windows? - wso2

Question

I'm collecting events with different id, there are n type of fixed ids in incoming events. I want to collect average of past events based on time-frame or no. of events between different type of ids.
Let's say, there are 2 devices sending data/ event with id 'a' and 'b'. I want to get average of past 5 minutes of data for both devices and then compare both averages to make some decision.
By this code, I'm collecting data of past n minutes of data and storing in 2 windows.
`
#source(type='http', receiver.url='http://localhost:5007/SweetProductionEP', #map(type = 'json'))
define stream InProduction(name string, amount int);
define window hold_a(avg_amount double) length(1);
define window hold_b(avg_amount double) length(1);
from InProduction[name=='a']#window.timeBatch(5 min)
select avg(amount) as avg_amount
group by name
insert into hold_a;
from InProduction[name=='b']#window.timeBatch(5 min)
select avg(amount) as avg_amount
group by name
insert into hold_b;`
window hold_a and hold_b will get average data of past 5 min. Now I want to compare data from both windows and take decision.
I've tried join on both windows but join query doesn't get executed.

Answer 1

You have to use a pattern to achieve this. Below query with output the name which had the highest average into highestAvgStream.
#source(type='http', receiver.url='http://localhost:5007/SweetProductionEP', #map(type = 'json'))
define stream InProduction(name string, amount int);
from InProduction[name=='a']#window.timeBatch(5 min)
select avg(amount) as avg_amount, name
insert into avgStream;
from InProduction[name=='b']#window.timeBatch(5 min)
select avg(amount) as avg_amount, name
insert into avgStream;`
from every(e1=avgStream -> e2=avgStream)
select ifthenelse(e1.avg_amount>e2.avg_amount,e1.name,e2.name) as highestAvgName
insert into HighestAvgStream;