firstLengthBatch (Window)
This is a batch (tumbling) window that holds a specific number of unique events (depending on which events arrive first). The unique events are selected based on a specific parameter that is considered as the unique key. When a new event arrives with a value for the unique key parameter that matches the same of an existing event in the window, that event is not processed by the window.
Syntax
unique:firstLengthBatch(<INT|LONG|FLOAT|BOOL|DOUBLE|STRING> unique.key, <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.length | The number of events the window should tumble. | INT | No | No |
Example 1
CREATE WINDOW CseEventWindow (symbol string, price float, volume int);
from CseEventStream WINDOW UNIQUE:firstLengthBatch(symbol, 10)
select symbol, price, volume
insert all events into OutputStream ;
The window in this configuration holds the first unique events from the CseEventStream stream every second, and outputs them all into the the OutputStream stream. All the events in a window during a given second should have a unique value for the symbol attribute.