timeLengthBatch (Window)
This is a batch or tumbling time length window that is updated with the latest events based on a unique key parameter. The window tumbles upon the elapse of the time window, or when a number of unique events have arrived. If a new event that arrives within the period of the window has a value for the key parameter which matches the value of an existing event, the existing event expires and it is replaced by the new event.
Syntax
unique:timeLengthBatch(<INT|LONG|FLOAT|BOOL|DOUBLE|STRING> unique.key, <INT|LONG> window.time, <INT> window.length)
unique:timeLengthBatch(<INT|LONG|FLOAT|BOOL|DOUBLE|STRING> unique.key, <INT|LONG> window.time, <INT|LONG> start.time, <INT> window.length)
Query Parameters
| Name | Description | Default Value | Possible Data Types | Optional | Dynamic |
|---|---|---|---|---|---|
| unique.key | The attribute that should be checked for uniqueness. | INT LONG FLOAT BOOL DOUBLE STRING | No | Yes | |
| window.time | The sliding time period for which the window should hold the events. | INT LONG | No | No | |
| start.time | This specifies an offset in milliseconds in order to start the window at a time different to the standard time. | Timestamp of first event | INT LONG | Yes | No |
| window.length | The number of events the window should tumble. | INT | No | No |
Example 1
CREATE STREAM CseEventStream (symbol string, price float, volume int)
from CseEventStream WINDOW UNIQUE:timeLengthBatch(symbol, 1 sec, 20)
select symbol, price, volume
insert all events into OutputStream;
This window holds the latest unique events that arrive from the CseEventStream at a given time, and returns all the events to the OutputStream stream. It is updated every second based on the latest values for the symbol attribute.