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Named Window

Provides examples on defining a named window, and summarizing data based on that. This example uses time window as the named window, but any window can be defined and used as a name window.

For more information on named windows refer the Siddhi query guide.

define stream TemperatureStream
        (sensorId string, temperature double);

define window OneMinTimeWindow
        (sensorId string, temperature double) time(1 min) ;

@info(name = 'Insert-to-window')
from TemperatureStream
insert into OneMinTimeWindow;

@info(name = 'Min-max-analysis')
from OneMinTimeWindow
select min(temperature) as minTemperature,
       max(temperature) as maxTemperature
insert into MinMaxTemperatureOver1MinStream;

@info(name = 'Per-sensor-analysis')
from OneMinTimeWindow
select sensorId,
       avg(temperature) as avgTemperature
group by sensorId
insert into AvgTemperaturePerSensorStream;

define stream TemperatureStream (sensorId string, temperature double);
define window OneMinTimeWindow (sensorId string, temperature double) time(1 min) ;	Define a named window with name OneMinTimeWindow to retain events over 1 minute in a sliding manner.
@info(name = 'Insert-to-window')
from TemperatureStream insert into OneMinTimeWindow;	Insert events in to the named time window.
@info(name = 'Min-max-analysis')
from OneMinTimeWindow select min(temperature) as minTemperature, max(temperature) as maxTemperature	Calculate minimum and maximum of temperature on events in OneMinTimeWindow window.
insert into MinMaxTemperatureOver1MinStream;
@info(name = 'Per-sensor-analysis')
from OneMinTimeWindow select sensorId, avg(temperature) as avgTemperature group by sensorId	Calculate average of temperature, by grouping events by sensorId, on the OneMinTimeWindow window.
insert into AvgTemperaturePerSensorStream;

Aggregation Behavior

When events are sent to TemperatureStream stream, following events will get emitted at MinMaxTemperatureOver1MinStream stream via Min-max-analysis query, and AvgTemperaturePerSensorStream stream via Per-sensor-analysis query.

Time	Input to TemperatureStream	Output at MinMaxTemperatureOver1MinStream	Output at AvgTemperaturePerSensorStream
9:00:10	['1001', 21.0]	[21.0, 21.0]	['1001', 21.0]
9:00:20	['1002', 25.0]	[21.0, 25.0]	['1002', 25.0]
9:00:35	['1002', 26.0]	[21.0, 26.0]	['1002', 25.5]
9:00:40	['1002', 27.0]	[21.0, 27.0]	['1002', 26.0]
9:00:55	['1001', 19.0]	[19.0, 27.0]	['1001', 20.0]
9:01:30	['1002', 22.0]	[19.0, 27.0]	['1002', 25.0]
9:02:10	['1001', 18.0]	[18.0, 22.0]	['1001', 18.0]

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