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Siddhi windows in wiki format |
from <stream-name> {<conditions>}#window.<window-name>(<parameters>)
insert [<output-type>] into <stream-name> ( {<attribute-name>}| ‘*’|)
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1. lengthWindowLength windows - a sliding window that keeps last N events.
2. Time window - a sliding window that keeps events arrived within the last T time period.
3. Time batch window - a time window that processes events in batches. This in a loop collects the incoming events arrived within last T time period and outputs them as a batch.
4. Length batch window - a length window that outputs events as a batch only at the nth event arrival.
5. Time length window (not supported in 1.0the current version) - a sliding window that keeps the last N events that arrived within the last T time period.
6. Unique window (not supported in 1.0the current version) - keeps only the latest events that are unique according to the given unique attribute.
7. First unique window (not supported in 1.0the current version) - keeps the first events that are unique according to the given unique attribute.
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1. sum
2. avg
3. max
4. min
5. count
6. median (not supported in 1.0the current version)
7. stddev (not supported in 1.0the current version)
8. avedev (not supported in 1.0the current version)
Aggregate function must be named using ‘as’ keyword, and this name will be used for referring that attribute and will be used as the attribute name in the output stream.
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A sliding window that keeps last N events.
From the events having price >= 20 of the StockExchangeStream stream, output the expiring events of the length window to the StockQuote stream. Here the output events will have symbol and the per symbol average price as their attributes, only if the per symbol average price > 50.
from StockExchangeStream[price >= 20]#window.length(50)
insert expired-events into StockQuote symbol, avg(price) as avgPrice
group by symbol
having avgPrice>50
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A sliding window that keeps events arrived within the last T time period.
From the events having symbol == 20 of the StockExchangeStream stream, output the both the newly arriving and expiring events of the time window to the IBMStockQuote stream. Here the output events will have maximum, average and minimum prices that has arrived within last minute as their attributes.
from StockExchangeStream[symbol == 'IBM']#window.time(60000)
insert all-events into IBMStockQuote max(price) as maxPrice, avg(price) as avgPrice, min(price) as minPrice
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A time window that processes events in batches. This in a loop collects the incoming events arrived within last T time period and outputs them as a batch.
From the events of the StockExchangeStream stream, output the events per every 2 minutes from the timeBatch window to the StockQuote stream. Here the output events will have symbol and the per symbol sum of volume for last 2 minutes as their attributes.
from StockExchangeStream#window.timeBatch(120000)
insert into StockQuote symbol, sum(volume) as totalVolume
group by symbol
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A length window that outputs events as a batch only at the nth event arrival.
From the events having price >= 20 of the StockExchangeStream stream, output the expiring events of the lengthBatch window to the StockQuote stream. Here the output events will have symbol and the per symbol average price> 50 as their attributes.
from StockExchangeStream[price >= 20]#window.lengthBatch(50)
insert expired-events into StockQuote symbol, avg(price) as avgPrice
group by symbol
having avgPrice>50
Supported units for time windows
The following units are supported when specifying the time for a time window.
| Unit | Syntax |
|---|---|
| Year | year | years |
| Month | month | months |
| Week | week | weeks |
| Day | day | days |
| Hour | hour | hours |
| Minutes | minute | minutes | min |
| Seconds | second | seconds | sec |
| Milliseconds | millisecond | milliseconds |
Note that each unit supports both the singular and plural format (e.g. second, seconds) and some units have a shortened form (i.e. sec, min).
Following examples use different formats available for 'minutes'.
from StockExchangeStream[symbol == 'WSO2']#window.time( 1 minute )
select max(price) as maxPrice, avg(price) as avgPrice, min(price) as minPrice
insert into WSO2StockQuote for all-events
from StockExchangeStream[symbol == 'FBX']#window.timeBatch( 5 minutes )
select max(price) as maxPrice, avg(price) as avgPrice, volume
insert into FBStockQuote
from StockExchangeStream[symbol == 'FBX']#window.timeBatch( 5 min )
select max(price) as maxPrice, avg(price) as avgPrice, volume
insert into FBStockQuote