SLIDING_EXPRESSION()
A sliding window that holds the last number of events defined by an expression at a given time, and gets updated for each arrival and expiration.
Syntax
WINDOW SLIDING_EXPRESSION(expression <STR>)
Query Parameters
| Name | Description | Default Value | Possible Data Types | Optional | Dynamic |
|---|---|---|---|---|---|
| expression | An expression that defines what events should be included in a sliding window. All possible valid expressions are allowed. | STR | No | No |
Example
CREATE STREAM cseEventStream (symbol string, price float, volume int);
CREATE WINDOW cseEventWindow (symbol string, price float, volume int) SLIDING_EXPRESSION('count() <= 20');
CREATE SINK STREAM OutputStream (symbol string, price double);
@info(name = 'query0')
INSERT INTO cseEventWindow
FROM cseEventStream;
@info(name = 'query1')
INSERT INTO OutputStream
SELECT symbol, sum(price) AS price
FROM cseEventWindow;
This query holds a number of events less than or equal to 20.