time (Window)
This is a sliding time window that holds the latest unique events that arrived during the previous time window. The unique events are determined based on the value for a specified unique key parameter. The window is updated with the arrival and expiration of each event. When a new event that arrives within a window time period has the same value for the unique key parameter as an existing event in the window, the previous event is replaced by the new event.
Syntax
unique:time(<INT|LONG|FLOAT|BOOL|DOUBLE|STRING> unique.key, <INT|LONG> window.time)
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 events. | INT LONG | No | No |
Example 1
CREATE STREAM CseEventStream (symbol string, price float, volume int)
from CseEventStream WINDOW UNIQUE:time(symbol, 1 sec)
select symbol, price, volume
insert expired events into OutputStream ;
In this query, the window holds the latest unique events that arrived within the last second from the CseEventStream, and returns the expired events to the OutputStream stream. During any given second, each event in the window should have a unique value for the symbol attribute. If a new event that arrives within the same second has the same value for the symbol attribute as an existing event in the window, the existing event expires.